If you search the Mordheim Yahoo Groups Forum history you’ll find the Mordheim Alternate Turn Sequence rules. Unfortunately these rules don’t work when multiple opponents are involved in melee.
So my friends and I play a derived simplified alternate turn sequence that I’ve just described to a fellow Mordheimer on the PitYak Studios forums. It works very well and makes for a more more exciting game of Mordheim than the original ‘I go, you go’ rules. Grab a deck of playing cards and try it out!
PS: I’ve also made the post text available here should the original forum message get deleted.