I also find that an extremely good way of doing things is: have one ally specialise in driller cap and one in driller production (that means player1 gifts tinkerers/MoE, drillers, and generators to player2 and player2 gifts smugglers/tycoons and factories to player1). You end up having a very integrated territory

but it works well. When you are being attacked your ally can just gift drillers to your front line quickly. And he acts as storage for drillers. since he doesn't own any factories he can have as many Moe's as he wants.