Just change attack animation damage point and backswing within the object editor to 0.001 and they will attack at extreme speeds with high agility/attack speed.
I think there is something in gameplay constants about max attack speed that you can increase, I'm not sure. But normally, attack speed maxes out at about 200 agility.
I've tested before, a unit can only attack approximately 15 to 20 times per second. This is when all Backswing/Pointswing/Attack Cooldown are set to 0.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.