NEW PLANS!
I have 3 strategies for this next turn.
In either case, we need to free American first.
1: We deal Wiremen an old-school anime-style beat-down. American starts off this Epic smack-down with his rageclaw, dealing force-blows to wireman to keep him off-balance. Broadside rushes in, and deals him a Gigas Fist slam using a mag-bolt 1. American combos off of that attack with another Rage Claw slam attack, blasting the navi into the air to set-up for the next attack. Broadside winds up, and swings an electrified Big-hammer 1/Elec Reel 1 into the boss, sending him into the wall. Then, for the finale, we all take aim, and fire everything we have into his stunned and broken face for the win. This probably wont kill him, but it will seriously put the hurt on him. American's unspent action will be used freeing himself from the barbed wire trap. American goes in swinging like Rocky.

((The elecreel will take care of the Heel Navis.))
2: American and Skully tag team Wireman, keeping him away from Nuller and Broadside while we combine our weapons to fire a blast similar in effect to the Deletion Cannon. Those bombs Nuller uses combined with an Elecreel, a Zapring, and using Add-Break ability should blast away most, if not all, of Wireman's armor. A fate worse than death: Paralyzed, armor-less, crippled, and totally vulnerable. Broadside's unspent action will be used freeing American from the Barbed Wire trap.
((Again, the Elecreel will take care of the fleeing enemies, if you don't first.))
3:
We drop the place on Wireman's head, dance on his grave, and call it a day. There is no 3.
If there's a better plan I'm not aware of or you wanna just thrash this guy on-the-fly, I'm ready for that too.