Very impressive, I cannot say I would have the patience or ability to legit do this myself. But I must point out a few missed opportunities. If you instead landed any holy order/mercenary leader as a KING, then killed them, YOU would get the title. I screwed around using only basic console cheats to swap around and change religions to give as many merc/religion titles I could to the Pope, for fun. I was able to make the Pope the Hochmeister/Grandmaster of all 4 Holy Orders, and Captain of the Varangian Guard(I would have done the Mamluks too, but the Fatimids were already in decline and since I was just screwing around and then watching in observer I didn't want to put the time in to get them an Empire title so I could give the Mamluks a king title, kill them, switch to catholic, give the title to the pope, then switch to observer and remove the now-catholic fatimid emperor. And as for the Ghilman Company, I didn't even realize they existed, don't play Muslims much. Are they Seljuk vassals?
Oh yeah, I also gave the Byzzies all of the other religious heads like you did, but I could only get them to be his vassals.
This reminds me, I need to play that save and see what the hell happens.(Unfortunately probably not much, as funny as the Papacy holding all those powerful titles sounds, I wouldn't see much of a difference in the game unless I gave them to Rus or something.)