There is no need to give the computer your resources. It doesn't affect its attitude towards you in any way. It just means you'll lose some of your resources, and that's it. But there is a way to take ALL of the computer's resources. :D

On the first day, you need to buy a hero in the computer's castle and collect everything that's lying around. Then, either return with that hero to the castle (at the end of the turn), or hire another hero and leave him at the castle gates. The goal is to prevent the ally from hiring their own hero. And that's it ;) You can spend the whole game like this - the ally stands in one place, and you collect all of its mines, stashes, artifacts, and resources that are lying on the ground...

This is much more than the ally can give you during the game. :)