Chronic unbalance between NOD & GDI

Nod only has the advantage late game. GDI has it in early game. You are correct however because Nod players often abuse/use the Cobra's shield. The shield grants it another 100% life without the need for repair time, so if the cobra goes into a fight without losing its shields, then its a major advantage. GDI doesn't even have the closest thing to a shield. Maybe if some of the research upgrades for GDI were replaced with like 50% repair time discount or a makeshift shield, it would be a game changer. Instead of trying to correct the balance, I would propose being able to research the opposing bases and/or mixed bases to remedy this issue. It would also resolve issues regarding multi-accounting if a player wants to play both GDI and Nod. I could imagine seeing GDI Orcas and Nod Cobras flying side-by-side in the same offensive strike. Such a combo would annihilate everything but the structures. Flak should however be baited by cobras.