http://2.bp.blogspot.com/_zJKhDVAd72Y/TOmq-uHw11I/AAAAAAAAAD0/NNCzUjMtPPo/s1600/Outnumbered.jpg

*Doesen't include enemy infantry unit movements, nor the moving units. New info: Heavy hero appears at right side, left side has marksman artillery moving slowly torwards the middle. Also Enemy infantry units run to middle.

I made a few maps myself but I'd recommend not to post them here. this will totally spoil the fun for players to find out the map layout on their own. You can post that you made a map and give it to those who explicitely ask for it. Otherwise coops will get boring as hell, just following someones step-by-step guide to think this further.

And by the way, you can't even win with this map, because half of the units that will approach you are missing.
(and the recon hero on the left side of the middle stands 1 hex northeast )

Agree with the first part
Laughed with the second part

It took me and Inferno about 10 tries until we made it and knew the moving pattern of every enemy, so I could draw you a very precise map of everything at any time (as with all other harder coops I've done - everyone feel free to ask me for help)