I will admit, the Irkalla wasn't really doing too well in Godsend; a few Patriots were enough to bring it down. I know it's balanced for multiplayer, but at the same time, I wouldn't have minded if they did a campaign only buff to it, much like Libra; maybe give it the Super Thor treatment? Make it so that it can fire a bunch of weapons all at once? As well as a massive health boost?
According to the Wiki, the Super Thor is pretty much an open topped, fire port capable Thor Gunship that has 5 Guardian GIs, 5 Siege Cadres, 2 Aeroblazes and a Battleship garrisoned inside of it. Maybe make the Irkalla in the campaign the same, only with Epsilon weapons? So something like 2 Oxidizers, 8 Archers, and 3 Marauders in an open topped, health boosted Irkalla? The Irkalla is supposed to be this flying warship of doom and destruction for the enemies of the Epsilon, so...
The Paradox Engine is the size of an Independence Day City Destroyer?! That is a really really really really really big ship then... holy ****, I didn't know that. Probably explains how that thing can hold the entire Euro Alliance army, the Pacific Front Army, a built in Chronosphere, a Time Freeze Weapon, among other things. Too bad the game doesn't allow it to be bigger in-game, but then again, a City Destroyer sized ship... that ship would pretty much be the map itself (Think RA3's floating fortresses; those things are so big that they're more or less the map you fight on, if that makes sense). Kinda surprised that they don't make a map where you fight on the Paradox Engine itself; it's big enough to do it, I think.