Ok, then the Mammoth Tank is ok.
I'm insisting on this since I think that the proper integration of TS in RenX would be an extraordiary improvement.
Let's start with a list of vehicles(including those who are already in):
GDI: Wolverine, Titan, Hover MLRS, Juggernaut, Disruptor, Mobile EMP, Mammoth Tank, Orca Fighter(Already in), Orca Bomber,
Nod: Bike, Buggy, Tick Tank, Artillery, Devil's Tongue, Reaper, MRV, Stealth Tank, Harpy, Banshee.
Obviously it is a match between the Strong and the Fast. GDI vehicles are more resistant, yet slower. This is compensated by the somewhat fast Hover MLRS. Furthermore, GDI has the Mobile EMP which disables vehicles for a certain period of time and the Mammoth Tank, the strongest(in terms of Damage, HP and Resistance) of ingame vehicles. The Aircraft is OK but it takes a combination of both Orca Fighters and Bombers to properly lead an attack. Bombers are quite effective vs structures (and vehicles) but cannot attack air.
Nod vehicles, on the other hand, focus on speed and damage-dealing. Nod players will have to play hit-and-run tactics versus GDI's frontal assault. The Banshee is a very powerful type of aircraft good vs other aircraft, vehicles and (not so much though) buildigns, while the Harpy is good vs infantry, aircraft and light vehicles only. The Nod artillery has longer range and stronger firepower(per-shot) than the Juggernaut, but the Juggernaut can fire 3. The Devil's Flame can lead some nice surprise attacks but I was thinking it should be expensive. Between the Tick Tank and Titan, the Titan is obviously victorious but it is slow, and easily countered with Bikes and Stealth Tanks. As for the Mammoth, the all-around, slow, strong GDI "superunit" has to be countered by tactical combination of various elements. Nod has also the Mobile Repair Vehicle(MRV) which is a huge advantage in protecting bases and repairing vehicles (since Nod vehicles are weaker).
To summarize:
-Where GDI is frontal attack, Nod is tactics and for every Nod tactic there can be a GDI counter-tactic and so on in an infinite cycle of strike and repel.
-There will be more aircraft and more importance to air battles, since GDI has the Orca Bomber which is dangerous to buildings. Still, even Nod has its own unit in a certain way, strong vs bases - the Devil's Tongue. (not too strong though, it is a flame tank and it is mainly an infantry counter.)
-The factions will have a slightly more unique feeling. For example, GDI will be characterized by walkers while Nod by light vehicles.
-The gameplay will be completely asymmetrical with every faction having a different type of gameplay.
-The Tiberian Sun mode will still be optional, so one can still play the classical Renegade X.
(Of course, much will be determined by the various stats as well as by the infantry of each side, argument which I did not treat since there is few infantry in TS and it would mean that some infantry would need to be invented.)