Pfeffersack
Deity
Yea, if you want to get a combat bonus, you are apparently going to have to play Miriam... and if you are playing Miriam, you should probably be popping lots of psych chaplains, using them for tech, and going for massively powerful Helions anyway...
... or paint poor Miri green

Regarding the fanatical attack, I can confirm both that you get it, when having a state religion and attacking wild NL and as well, if you attack someone w/o a state religion. That should be changed, IMO.
Attached is a save showing both cases. If you let display odds for the selcted siege tank vs. the NL infested base "Amnestiedorf", the bonus gets displayed. If you declare war on Lal and move the siege tank S-SW-SW, "Gleichheitsdorf" comes in sight. Again you will see the bonus when showing combat odds here.