[Oversway]

Low gem does favor blood, and very difficult research also gives a boost (since you only have to research blood and perhaps construction paths).

On such a small map, I think a higher gem setting might help. The idea is you won't get into high enough research levels to be summoning lots of scs before the game is over.

On the other hand, lots of gems may mean lots of spell casters and low level summons. Which may not be what you had in mind.

Another option is a mod that disables all the magic above level four. I recall there was an mp game with that, you can probably get the mod from that thread.