I've seen this in "Barendreth, Lower Level", but it might well be happening in the other parts of the stronghold as well.

Why shouldn't ordinators summon clannfear? First, it is weirdly unorthodox for a bunch of ordinators to summon bad daedra. But gameplay-wise, it makes the situation far too confusing: To the player, daedra are daedra and call for the sword. There are some hostile dremoras in the stronghold that clearly deserve this treatment. But attacking the summoned clannfear turns the ordinators hostile, which is hardly the intent.

PS. If the purpose is to make the ordinators less likely to die, maybe spell absorption/reflect would be helpful.