Quote Originally Posted by Caliburn
Oo, you're right. Their stats in crusadersunit show that they only have an effect on how fast the population is converted, which means they're about 2,5 times more effective than a bishop.

But still, I've used them for upping the zeal in several campaigns; is it just a coincidence that the zeal of the provinces where I've posted a few cardinals has been boosted to 80-90 %?

There might be other factors to it, of course, but maybe their "religious bonus" still has some positive effects on zeal in 100 % Catholic provinces?

Well, maybe it's just a coincidence, maybe the Chapter house has an effect or something. Pious governors cannot explain it all. Any ideas?
The zeal is quite complicated as there's a bunch of other factors affecting zeal that afaik are hardcoded (but I'm not a serious modder).

I guess you can try and see if the zeal will be affected by cardinals in a 0% zeal province (late middle east for example). They shouldn't be affected by other zeal effects during that time, and can be pulled up to 100% by inquisitors.