Renewable resources for trees and critters sounds about right, i remember expecting AoM to do that when i first started playing it. I'd just leave a few deer in a nice wooded area, wall them off and hope they'd breed. What you could do is just set the gaia ai that controls all the animals and trees to build new animals and trees from the ones on the map, give them a longish build rate and only build one at a time. Next thing you know the areas you aren't currently gathering from get loaded with wildlife. I like this idea better than watching the enemy run out of resources and sit there waiting for me to kill them. I play to play not to win. As for the other resources such as stone and metal, metal could be generated thru some sort of factory, workhouse, or trade function. Stone and wood and even metal you could get more of by recycling buildings. Set it up so that when a building is destroyed either manually or thru war rubble takes it's place like in aom. But make the rubble a gatherable resource representing like 75-90% of the buildings required materials. This also means that if you get done with a building and want to build something else in it's place you can do so without it being totally wasted.