The AI is set to build and train. In M:TW it was the same except that it wasn't too good on the finance side so lots of factions were dirt poor. However when giving the AI plenty of money (either by upgrading province income or lowering unit costs) it can do what it does best; spending dinari. So yes, it will certainly help, but you should take notice of the increased stress on population levels. Settlements shouldn't run dry.