I wanted to do an update in case anyone was interested:
I did two starts, and in both the alternatives were the Jagiellon or a very high stat Polish noble. In both cases I chose the Jagiellon - thanks for the help! - because what became really clear to me was how poor Lithuania's provinces are. Supply limit alone is ... painful.
On the upside, Polish cavalry. Yeah. By the time I got winged hussars, my armies could roll over the enemy. I revoked Moldavia's march and annexed them easily (raised their opinion to 200, revoked march, waited ten years and repeated to annex). By 1462, I had Cossacks and then had the +20 Cavalry combat bonus. I also followed a path Arumba explored during his last Poland game where he rented out his armies to Novogrod. I raised my army to force limit, split it in half, then rented half to Novogrod while using the other as a reserve and to increase professionalism. Every so often I'd switch them out. Novogrod was always fighting someone, never refused the offer, and the money was very helpful early game where I seemed to suffer a bit from insufficient funds.
All that fighting on Novogrod's behalf did give me enough Army Tradition to get a passable general with two shock pips. At that point I could begin to expand without problem. Then I decided to restart this afternoon to make it more efficient.
So if I can ask two more questions:
1. Is it worth it to Westernize? I'm not doing a WC and my primary goal is to expand eastward and take over Muscovy/Russia. Another option is to try and early game roll into the Ottomans by allying with Byzantium.
2. I'm currently running 8/6/4 armies. I have two and they seem invincible (obviously, I'm not chasing a stack of 30 with these). Mid-game, I was thinking of adding two more cavalry. I feel like Poland could pull this off and ducat for ducat, it would result in a more powerful army (and, yeah, winged hussars on the map.) Assuming I'm going for Noble Knights and Finest of Horses, too.
I'm considering taking espionage for the Noble Loyalty Act (it is +20% combat ability) but that would be the ONLY reason I'd take it and that seems kind of a waste of idea points just to get 20% Cavalry Combat Ability. But it is 20% and totaled with my other buffs would give me almost 100% CCA. Do people think it's worth it?
Thanks again for your help earlier.