MLP Generations Timeline

I thought about the different generations of MLP and how they would fit into a timeline. This is what I came up with.

Generation One: Very ancient Equestria where the pony tribes all live together in peace before being separated. This is thousands of years before Luna and Celestia. The ancient Equestria is known as 'Ponyland' at this time.

Generation 1.5: A few hundred years after very ancient Equestria. Still way before Luna and Celestia. Still before the pony tribes have separated.

Between Generation 1.5 and Generation 4: There's some unspecified event that splits up the pony tribes for a long time and causes them to live separately.

Generation 4: At some point the pony tribes are reunited. Celestia and Luna become the rulers of Equestria. Then Twilight Sparkle takes their place.

Generation 3 and 3.5: These take place after Luna was banished to the moon but way before generation 4 starts. So it takes place during the sole reign of Princess Celestia. There would probably be some natural isolation that occured at the time, not out of conflict but maybe hiding from Nightmare Moon. A lot of the tribes would have gone into hiding as Celestia used the Elements to banish Luna to the moon. Which explains why the tribes in generation three were fairly isolated but all still got along.

Generation 5: Way after generation four when the tribes are split up again before Sunny reunites them. During this era Sunny and her friends become the new protectors of Equestria.

These are just some thoughts I had about putting all of the generations into a timeline of world events. What do you guys think? I'm curious to hear your thoughts.