Well, I'm through with the game

[Twan]

I don't find time to continue these games, but had good experiences of challenging SP in dominions 3, using boosted AIs (with mod and map changed to give them immobile researchers, more gem income, better scales and pretenders etc...). Of course the AIs are still stupid, but if you give them about 80 RP / 20 gems a turn at start, they tend to use their mages more.

I guess I should post my AI boosters on the maps&mod forum one day.

[llamabeast]

Yep, as Twan says, you can use map commands to design the AI pretenders yourself, and then they can still be on Impossible or whatever. You can easily set it up so that the game is extremely difficult to win.

I have to agree that in the late game the AI can't compete with things like SCs and ingenious use of battle magic. But difficulties like death scale use are very easy to fix.