Derpyfan 
[@Shimmering Spectacle](/images/2994971#comment_10323363)
No a century is too recent for that to have been when the tribes divided. Don’t forget that before the events of the movie no pony except Argyle and Sunny believed that the three tribes ever lived in harmony and had even thought that they had been in active conflict in the past. This tells us that several generations have passed since the division and anyone from that time is no longer around.
It’s more likely that the tribes had been divided for over a thousand years possibly even close to two thousand.
No a century is too recent for that to have been when the tribes divided. Don’t forget that before the events of the movie no pony except Argyle and Sunny believed that the three tribes ever lived in harmony and had even thought that they had been in active conflict in the past. This tells us that several generations have passed since the division and anyone from that time is no longer around.
It’s more likely that the tribes had been divided for over a thousand years possibly even close to two thousand.