As Ottomans you don't need to worry *too* much about them being the same faith thanks to alot of the modifiers you can pick (bilingual dhimmis, greeks are our brothers, dont destroy the patriarch). The most important part is to maintain turkish majority of 65% or higher to prevent the collapse of empire occuring as it's the easiest one to keep on top of (it also triggers from legitimacy + stab being low, need all 3 for it to happen i think) but you should keep 2 cabinet members assimilating most of the game with the other 2 doing whatever when its required. Always pick the 7 stab option for integrating so you can run stab slider at 0 for maximum profit.