So I did MLP-EG/Pokemon Profile Crossovers, where I had the Main 8 as a Elite 8 which would the final bosses of a Pokemon game to become champion. The trainer template was done by Kuching-Sama on devianart

6719655 I can see Applejack, Fluttershy, Rarity, Rainbow Dash, and Sunset's teams and type choice suiting them well.

Though for Pinkie, Twilight, and Starlight, i have some doubts. While Pinkie may be quite random, psychic doesn't seem to suit her. Maybe normal or fairy types rather. And the psychic team would be better for Twilight than ghost types. And Starlight... i don't exactly see how a dragon type team suits her

6719817
Okay so I forgot to say this, but the 8 of them originally were supposed to be gym leaders. With Celestia, Luna, Cadance & Shining being the Elite 4, but when I was doing Sunsets team I decided then and there the 8 of them would be the Elite group of trainers.

Cadance's team was Fairy, Shining's was Fighting, Celestia's was Psychic and Luna was Ghost and after I decided not to use them I wanted Psychic and Ghost used. I gave Pinkie Psychic because she's unpredictable in what she does and giving her a type that you wouldn't expect made sense to me. Twilights ghost because I already gave Psychic to Pinkie and Starlight always had Dragon.

6720027 Pinkie may be unpredictable yes, but psychic is hardly her type in my opinion. And i hardly see Twilight having ghosts on her team, which would just make her hair go haywire like when she tried studying Pinkie.

And what do you exactly mean with Starlight always had dragon?

And just so you know, all of this is just an opinion. I'm okay if yours is different

6720060
What I mean by Starlight always had Dragon was the Main 8 were originally gym leaders Starlight had Dragon types then when I choose to make then an Elite 8 Starlight kept Dragon.

If you want to know Twilights originally team was Electric and Pinkes was Water

6720078 Still doesn't completely answers why Dragon types suits Starlight to be honest

6720088
I honestly had no idea what to give Starlight so I just gave her Dragon

6720105 Maybe give her Dark types.

6720115
fixed the Twilight & Pinkie team problem look at the teams now

6743375 Not bad.

6743375
Hmm... I realise you have some difficulty with Starlight, so I won't object there, but I do wonder about Fluttershy and Rarity. Grass is... OK for Flutters, but I think Normal would work better with her retiring nature. (She could squeeze a killer bunny in there somewhere too.) As for Rarity, I'm quite certain that she should be Rock - those aren't ice crystals on her flank skirt. Though finding beautiful ones might be tricky...

And I do think that them as Gym Leaders with the others as Elites makes more sense. But it's your project at the end of the day.

Fluttershy with a Normal Type Team

If you are going to have an elite 8 than you need more than 18 types of pokémon to justify having that many elites.

Here is how I feel the 12 you posted would pick their respective pokémon if based on how I understand their respective canon personalities.

1. The human Applejack would go with the Physical type if it exists, dough not necessary the physically focused of the lot. While the pony Applejack would go with the Fertility type if it exists.
2. The human Fluttershy would go with the Compassion type if it exists. While the pony Fluttershy would go with the Critter type if it exists.
3. The human Pinkie Pie would go with the Variety type if it exists. While the pony Pinkie Pie would go with the Willpower type if it exists.
4. The human Rainbow Dash would go with the Body type if it exists. While the pony Rainbow Dash would go with the Flying type.
5. The human Rarity would go with the Beauty type if it exists. While the pony Rarity would go with the Artificial type if it exists.
6. I don't have a clue want the human Starlight Glimmer would pick if she exists but the pony Starlight Glimmer would go with the Spellcaster type if it exists.
7. I also don't have a clue want the human Sunset Shimmer would pick if she exists but the pony Starlight Glimmer would go with the Shadow type if it exists.
8. The human Twilight Sparkle would go with the Knowledge type if it exists. While the pony Twilight Sparkle would go with the Arcane type if it exists.
9. The human Celestia would go with the Humonoid type if it exists. While the pony Celestia would go with the Laughter type if it exists.
10. The human Luna would go with the Data type if it exists. While the pony Luna would go with the Dream type if it exists.
11. The human Cadance would go with the Hope type if it exists. While the pony Cadance would go with the Love type if it exists.
12. The human Shining Armor would go with the Energy type if it exists. While the pony Shining Armor would go with the Guardian type if it exists.

Also don't have your bosses use too many pokémon from other regions as it just comes off as a clutch. Rather try to have a decent amount of each boss's pokémon coming from the region they are a boss in.

7066885
Cool - still needs killer rabbit though. And maybe a bear (though Snorlax might do for that).

7067378
I could just simply change them into Gym Leaders and their teams would stay the exact same