[Burnsaber]

How about if you set the composition of "Pantheon" in stone at the start of the game? Like that a pantheon can at max, have a King/Queen/Lord of Love/War/Wisdom/Death. The King and Queen of the "last standing" pantheons are "winners" while the "Lords" share a second place. Or you can just have King be "1st" and Queen "2nd" and so forth. (this way, people can be bribed to switch sides, "Heck, who wants to be lord of death, you can be the king in our pantheon!")

And I don't know if it would work, but you could also impose a rule that you can only be a lord of "X" if you fill some thematic requirements. B6F6 Moloch as the "Lord of Love" is a "no-can-do". Of course the reguirement for being King/Queen is just being powerful enough (and the right gender, of course). This would prevent the "the six most powerful nations form a pantheon and win" problem, since it's unlikely that they could form a legal pantheon from their gods. This would force alliances to form between not-so-optimal players and nations (and make pretender design a bit... complicated, to say in the least).

You'd need a out-of-game "judge" to decide whenever a certain god can be a thematic fit for a "lord" position, thought. (I volunteer, since it's very unlikely that I'd join a game of such epic scale)