Well, I'd speculate that the Western nations also used heavy cavalry right up until firearms were effective enough to defeat them. They would have used a higher ratio if they could, but poorer cavalry tradition + more population to recruit infantry meant they didn't.
Plus the Swedish also had an incredibly high cavalry ratio (at least in the later part of the period) yet I don't think they should migrate to Eastern tech...
TO having more knights: Well I suppose that's because they were a Knightly Order and their (early) military consisted mostly of foreigners, including many knights? Maybe that's just a story, I'm no expert. Well I suppose they might be men-at-arms without actual knighthoods.
I don't see AI monastic orders surviving all that much, so nerf is unneeded in my opinion.
Actually crossbows made knights inefficient nearly a century before firearms showed up in europe, and a century after the firearms showed up in europe the crossbow was still a superior weapon in almost every respect. The reason they went for firearms was the moral effect of the sound on men and horses.
The crossbow changed the battlefields of europe, it allowed a peasent with minimal training to stand up to a fully armoured ad trained knight on almost equal odds. And you could train and equip a dozen crossbowmen for the price of a knight. In the east the crossbow never really caught on and they kept using medieval tactics (or not specifically they evolved in a diffrent direction from the medieval tactics, more towards light cavalery) until the firearm came into wider use.
And sweden should perhaps be eastern tech too, up until the military reforms of Carl XII. Sweden has always been culturally more connected to eastern europe, despite the westwashign of our hisotry we've been doing in the last century.
You speculate a lot on things where wikipedia could enlighten you.
And you don't see the ai monatic orders doing increadibly well? In my last three non monastic games the livonian order has conquered russia twice and the teutonic order all of the commonwealth (which didn't form a single time, not even the PU) once. Is it just me?