User blog comment:So-Pro Warrior/Season 1-Battle 8: Battle of the two Forces of Good Armies: The Systems Alliance vs. The Grand Army of the Repubic/@comment-422690-20130326232605

I'm going to start off by mentioning that I know next to nothing about ME, and I haven't watched the Clone Wars series at all. This will be based mostly on their forces and situation rather than their commander or the environment, since I don't know the environment for either planet.

Eden Prime:

I think the Systems Alliance will take this one with ease. They are not only entrenched in a defending position, their arms and armor are ideal for it. Their sniper can nullify any cover the opposing force finds. The Clones are an excellent assault force, but their strength lies in being capable of thought as well as disposable. The Alliance is much more combat-capable, especially with energy shielding and force-mimicking Biotics.

Horizon:

The GAR takes this, but barely. The Alliance retains their advantage in tech, but the GAR has the advantage of a defensive position. This will give them that extra push needed to come out ahead, but they will still take massive casualties. The survivors from Eden Prime could finish the job.

Space:

This here is the big balance shifter. If this was based on the round war alone, or if the space battle was in random-ass space, the Alliance would have swept this. However, this battle is over Earth. First thing, is that the Republic would take this either way, thanks to the overwhelming firepower advantage from the ships themselves. Any boarding parties can be taken care of quite easily by both sides, thanks to inner defenses. The fighters will provide support, but ultimately the immense power of the Republic fleet will win against superior numbers. The fleet would be wounded, but not crippled. The fleet can then hold Earth hostage, giving the Republic a phyrric victory.

Overall winner: GAR wins, despite taking the heaviest losses.