Yo, I Feel Like Writing a Rambly Essay Thingy · 5:19pm Jun 8th, 2015
Because they're fun. Because it's not a school assignment. Because I'm not in school right now. 
So, you guys all know my main schtick on this site, namely these dorks:
I write this more than CheesePie, what the hay?
So, I suppose you're wondering if I have any rules for writing them that I have to follow (and if any of you decide to write them, these apply to you too). Well, let me lay down the law on Sandwich Brother literature.
Compare and Contrast
First off, they do sort of follow the Maud-Pinkie relationship--having simultaneously everything and absolutely nothing in common. Tomato--well, after that failed first attempt (*shudder*)--represents what could have happened to Cheese had he stayed in Manehattan. Grumpy, sarcastic, businesslike--you know, the works of a busy city. And if you noticed in the episode, Cheese does kind of treat his special talent more like a business than Pinkie does (but parties are serious)--only he's paid in smiles and laughter rather than bits (they never quite say whether or not Cheese earns money off it). And it requires a closer look, but he is more serious and down-to-earth (and shyer) than he lets on. I remember that during my first time watching Pinkie Pride, I was thinking that Cheese's acts in the Goof Off were kind of forced.
Of course, for our Sandwiches, the reverse is also true--Tomato could have easily become a party pony, because he is actually kind of weird and has a big heart. As hard as he tries to be the "normal" brother, Tommy is not quite above that kind of stuff, and in Brotherly Bonding Time, he's actually been referred to as a "kid" more than once (the Flim Flam Brothers actually made fun of him for trying so hard to come off as an adult when he still doesn't quite understand what it means). And in one scene, when he gets excited over his talent, boy, does he get excited! (Of course, he might go back to being discouraged about it, since it did kind of lead him into trouble recently.) And as snarky as he gets, it's more of a defense mechanism than him actively being malicious.
And one of their common points is the fact they both can sing really well.
Also, friendly reminder about their colthood:
So, a tweak in the Sandwich Bros timeline could have easily lead to this:
Somebody thought that tweak was who ran away, but I don't really think so. It could be just a simple story of Cheese--now accordion-less--forced to accept his mother's demands, and Tomato trying for years to make it up to his big brother after the accordion incident. These talents ensue.
Big Brother Cheese
Now, most people who'd give Cheese a sibling would just make him the younger sibling. After all, younger siblings are the more whimsical and less serious types that are either precious cinnamon rolls or brats that you want to push off a cliff (Cheese would be the cinnamon roll).
Thing is, I have an older brother, and I'm an older sister as well, and I ended up seeing both of us in Cheese. Thus, I made the conclusion that if Cheese had a sibling, it was a younger sibling. So, when I started to create Tomato, I had Cheese pegged as the oldest of the family.
So, how is he as a big brother? He'd be completely awesome, right? Wouldn't it be fantastic to have Weird Al as an older brother?
Well, friendly reminder that there was a feud, guys, and it was a two-way street. Please don't tell me you think Cheese was completely innocent the whole time--his actions did carry a lot of weight, just so you know, even if they seem few compared to Tommy's multiple screw-ups.
Of course, true to what we saw in Pinkie Pride, once it hit Cheese that he had his own crimes that only made things worse, he quickly set out to make things right. When the two buried the hatchet, Cheese's shift in attitude goes into being the playful and protective older brother he's supposed to be. He's found that he still has to keep Tomato out of trouble, despite the latter not being as hyper as he was as a colt. And he is more willing to show affection toward Tommy in public--coming in the form of noogies and drawing him to his side in a hug.
Not to say that Cheese has become the perfect big brother. First off, he sometimes does treat Tomato as if he was still a little kid that'll get in the way, and sometimes babies him as if he completely forgot that his brother did go through puberty and does not appreciate that. And then when he's reminded about the personality shift, he's just confused and annoyed with it. In fact, Cheese doesn't really have that much respect for Tomato's special talent, and he's been casually deriding it lately. And lastly, he actually does find Tomato annoying at times, and does sometimes tease him (come on, siblings tease each other). At times, he can come off as neglectful, which he excuses with "I was busy".
Hey, Cheese can't be the grinning party pony all the time. I like my Cheese with varied emotions.
Little Brother Tomato
Now, how would you handle Tomato as a little brother?
As an adult, he's that quiet pony that'll prefer to read in the corner, simply because he's bored. He's quite often well-dressed, always wanting to make the best impression without saying a word. He's quite polite if you're on his good side, and if he likes you, he'll slowly warm up to you over time, revealing a curious and funny colt that's willing to help you in a pinch. He's not as affectionate as Cheese is, but when he gives you a compliment with a sweet tone and a smile, he really means it.
Of course, he's secretly quite confused and underconfident, underneath the suit and tie. He's frequently on emotional lockdown, which tends to have the effect of having him explode later on, which leads to him being ashamed for not controlling himself because, you know, he's supposed to be a strong, composed stallion focused only on the talent his cutie mark represents--like his mom says.
However, Cheese is often faced with Tommy's thick and prickly outer shell, which shields the sensitive and emotionally-wounded colt from any more harm. He'll deliver snarky asides and casual insults to just about anyone--including himself. This aspect of Tomato is his most obvious personality trait, which tends to frustrate and annoy Cheese. Also, Tomato's kind of stuck in a "darned if you do, darned if you don't" situation--if he doesn't help Cheese with a party, he'll be accused of laziness; and if he does, well, he might get in the way and screw something up--and he's well aware that Cheese treats him differently (as in, kind of meaner) from other ponies. He prefers the safer option--not doing anything.
And then there's the colthood personality trait of impulsiveness that crops up from time to time, and his habit of getting into stupid situations doesn't seem to be dying out anytime soon. Poor Cheese is rather put upon...
The Feud
Brotherly Bonding Time is mainly about Cheese and Tomato recovering from their feud and rebonding as brothers by going on a summer road trip together. Results vary as much as the weird adventures do.
So, what started the feud? Well, to put it shortly, in their childhood:
Cheese: "Unneeded", painfully shy and lonely, bullies, under Mom's hoof, jealous of Tommy's grades and popularity, grieving grandparents' deaths, upset after the accordion incident (so upset that his efforts to cheer Tomato up during adolescence were insincere), becoming rather detached from his family, feeling underappreciated for his efforts to protect and love his brother, and finally, his special talent is not taken seriously.
Tomato: "Unwanted", oblivious and insensitive about Cheese's problems, overexcited over making new friends, frustrated at Cheese shutting him out, guilt over the accordion incident, abandonment issues, bullies, ends up taking Cheese's place under Mom's hoof, jealous of Cheese's freedom, feeling like "Plan B", sensing Cheese's insincerity in his "cheer up" antics, and finally, still feeling like he's treated like a kid for his mistakes.
Yeah, what seems like a tale of "who's the favorite" at first turned out to be really complicated. The sad thing is, when they were colts, there really wasn't any solution to this problem where both of them could end up happy instead of just one.
Unless their mother had a sudden change of heart and actually tried to learn more about who her sons are than judging them by their academic prowess and later on their cutie marks. And if their dad stopped being a workaholic and played with them more. But, alas, those two are not changing that easily. 
Anyway, it's important to keep in mind that they had a feud, and they're not completely as buddy-buddy as they were when they were little. They're trying, but not quite there yet--and even then, they can't revert back to their original personalities.
Conclusion
If someone were to write these two in a fic, it's important to remember that even though Cheese is the silly party pony and Tomato the serious business pony, they also have the traits of protective big brother and admiring little brother--with of course them being annoyed with each other, not quite understanding each other's talents, and having their moments of goofing up.
At least they've got friends that encourage them to keep going. 
Now... I better write the climax of the Las Pegasus arc soon--let your brotherly love spur you to victory, Cheese!
And if any of you are curious about any other subjects, let me know. 
As their names indicate, the insides and outsides of the Sandwich brothers are very different things. A nice breakdown of what those differences are, how they developed, and how they impact the brothers now.
Also, I do love that sandwich/suitcase cutie mark on alternate Cheese.
To be fair sketcha I like anything that inolves the adorkable cheese boy since HE NEEDS MORE LOVE! So it's cool to see more cheese from you whether it's with his brother or pinkie.