The question isn't really whether it's possible, it's whether the AI is capable of doing it -- and also whether converting to feudalism effectively becomes a bad idea unless you've gone out of your way to carefully cultivate both yourself and your vassals for the event (and the ability to get your vassals to convert is generally out of your hands, anyhow).
I'd agree that it's currently too easy -- but, like I've said before, simply reverting to the old method ignores the fact that it also had some serious issues on the gameplay side.
I'd agree that it's currently too easy -- but, like I've said before, simply reverting to the old method ignores the fact that it also had some serious issues on the gameplay side.