If there were shackles and a crimson sphere, the Archmage (just the Archmage, without all the other machines) would have crushed this army. In general, the heroes are too inconsistent. Because against 14 Archmages, it's not even a contest, it's just... well, having 14 Archmages against nothing and losing is really frustrating...
P.S. I have nothing against a sphere with a cloak or shackles, I just found that assessment a bit off-putting.