Zech II. Use the threat of the guns to keep Five Thrust at Freddie's from going berserk on your DropShips, and use your missiles to conduct long-range bombardments of his DropShip formations. Aim for smaller ships if you can, better odds of getting kills. Cost him a Star here and a Star there, pretty soon his force is bleeding mechs and can't match you on the ground.
Keep pickets in space, at long range. The more warning you have when he tries a high speed run with the Fred, the better.