[thejeff]

I don't think the theme requires power gaming.

Thematically, Gods are focused on their spheres. A god of life isn't going to pick up a few levels in Death, just because it's a powerful, easy path to break into.
A god of war will fight. A god of honor will not betray, even if it's to his advantage. A god of treachery will, even if it hurts him in the long run. It's his nature.

They are, far more than mortals, expressions of that nature.
A god of life who turns to death to defeat death is no longer himself.

They are dedicated to winning, but will not act outside of that nature to win.

Another perspective on it, anyway.

(Most of which I promptly ignore when playing.)