Setting indies to strength 7 seems to be fairly optimal against impossible AIs. It slows down the player's early expansion significantly more than the pathetic str 5 indies but allows the AI to make large gains early due to the resource and gold bonuses it gets. Depending on the AI nation and its scales, you may come up against quite a juggernaut and with difficult research it can be hard going.
Map editing commands include a #cannotwin command which excludes a spesific race from VP victory. That combined with cumulative victorypoints would do what you wanted.
Not setting to many AI's for the moment . AI have trouble sieging enemy AI castles in latest version and will have their giant armies standing around enemy castles doing nothing.