If there is a pair of coexistent necessarily omniscient and necessarily morally perfect omnipotent agents, then there is a pair of incompatible contingent states of affairs each of which is morally optional for these agents, that is, neither morally prohibited nor morally required for them.
If a plurality of coexistent omnipotent agents were even possible, then possibly, at a time, t, some omnipotent agent, x, while retaining its omnipotence, endeavors to move a feather, and at t, another omnipotent agent, y, while retaining its omnipotence, endeavors to keep that feather motionless.
Intuitively, in this case, neither x nor y would affect the feather as to its motion or rest. Thus, in this case, at t, x would be powerless to move the feather, and at t, y would be powerless to keep the feather motionless!
But it is absurd to suppose that an omnipotent agent could lack the power to move a feather or the power to keep it motionless. Therefore, neither x nor y is omnipotent. This line of reasoning appears to reduce the notion of a plurality of coexistent omnipotent agents to absurdity.