And yes, the same Leva, Cerbi, and Roach were released before RoB, and before that, they weren't as overpowered as I understand from the discussions. Actually, I don't even remember Cerbi from the time of RoB; everyone was just playing with the normal Shadows.
They simply don't want to touch the Legion because there will be too many free wins. If they slightly nerfed Hector, the mid-range Shadow wouldn't suffer too much, but other factions would have an easier time, and the win rate against the Shadow wouldn't be 5%, but at least 25%.
Of course, I'm exaggerating.
🏹🎪+⛓️♿=💕