The Horses cannot get through the Fortress wall themselves yet, giving the Wolves months to repair, heal and move forces in preparation. Sure, it is no longer the 14 galaxy (+3 regiment & 1 oversized Warden galaxy) that participated on Terra but they are also going to be better troops than what the Horses could bring. Seven (at least, more likely 9) Wolf galaxies, one Falcon galaxy (and bs, there are more than that left), a galaxy or two of Jaguars, and oh yeah, 10+ warships with flotillas of assault DS . . . the Horses could not bring enough to take Terra, especially in contesting the ilClanship they would be considered dezgra by the forces on Terra.