[Omeganitros]

Oh, MAN. I just finished Mission 6, and I gotta say, this is the ultimate beat-all combo:

Completely Upgraded and Fully Reinforced Space Marine Squad + 4 Missle Launchers + Completely Upgraded Squad Sargeant + Apocathary
WITH
Completely Upgraded and Fully Reinforced Space Marine Squad + 4 Plasma Cannons + Completely Upgraded Squad Sargeant + Completely Upgraded Force Commander

It's only two squads, but they're absolutely DEVASTATING. While the Apocathary hangs in the back with the missle launchers and safely heals everyone, the Force Commander's squad fills the infantry up with lead before they even get close, and if they DO get close, the Force Commander goes "SPACE MARINES, CHAAAAAAARRGE!" and goes Melee and they're effing dead. Plus, if they run into any light vehicles, The Force Commander squad can take the brunt of the force while the Apocathary's squad nails it with Missles. I think this combo is even more devastating than the Librarian Squad + Force Commander Squad, even if the Librarian has Word of the Emperor.

Edit: Above combo applies when more than 25% of the enemy's infanty is Heavy Infantry. If it's all light infantry, use Flamers isntead of Plasma Cannons (Heavy Bolters may be tempting, but then both squads can't be moblie while shooting).