It depends on what result we're going for. From a strategic standpoint... we can't defend ourselves, so protecting ourselves by stockpiling defense isn't going to do anything. If we're trying to be merciful, one option would be to play all our attack stones on one team and hope it comes out to a fairly clean death. Otherwise, we can try to cancel out our attacks as much as possible. Alternately, we play favorites and protect the teams we know well while giving up on the others.