>>17835261
And he's not the only one to have reported this about them so I don't discredit it even if he was known to tell a tall tale.
>Their armies would've been larger than most European armies by an order of magnitude
Well in the second Mongol invasion of Hungary the lower estimates made them pretty much equal (I don't trust those exaggerations) and the for first one as well.
>Castles can be garrisoned by a few dozen men and have provisions for years.
In this particular case they allowed trade though iirc so this is irrelevant I believe. Also I am not sure why you believe a less well defended structure could resist better, given the fact the same exact tech and tactics can be used against both. Don't forget a city has way more resources to repel attacks, it's not just a bigger population