I agree that the mammoth shouldn't have a faster turning radius or faster in general... the original mammoth was REALLY slow! and was easily destroyed. The problem with having two completely different sides (Nod & GDI) is that their soo different it IS REALLY difficult to balance dissimilar powers (stealth vs armour)?Nod was designed as a stealthy, fast & light attacking organisation. GDI was stupid and basically worked on bruit force!
Like you said, stop complining. Grit your teath and learn how to play with GDI... they may be slow, but if you get into their base (oh mamma!) cannons vs the buildings rockets vs infantry.. you're unstoppable! 