doctorbadwolf
Heretic of The Seventh Circle
Anything quasi-European should have stuff from outside Europe in it. Europe has never been remotely isolated in recorded history.And really, there's a reason for that. If the game wants you to traipse around in dungeons, there's not much place for a shining knight astride a valiant steed, so making a class (or subclass) based around mounted combat is actually less problematic, apparently, than shoving a kung fu guy into your quasi-European fantasy game.
And enough folks eschew dungeons that there would be nothing wrong with putting mounts more front and center in a single class.
The Cavalier fighter would be cool if it wasn’t randomly also the defender fighter.Plus, if you have to rely on a real horse, and not a magical horse, ala the Paladin, that presents it's own problems.
Though, as an aside, I would find it hilarious for Cavaliers to become a subclass of Paladin, the complete reverse of 1e's Unearthed Arcana.
5e doesn’t do a good job of having the sort of warrior who has a bond with a mount and fights astride it using speed and agility, light and ranged weapons, and hit and run tactics, in spite of that being a very common historical warrior archetype. It’s odd.