I still think the Mammoth Mk2 would've beat the **** out of Nod, ala AT-AT style.
The Mark 2 was a vast disappointment to me, as it did not seem capable of handling or dishing out the kind of punishment to justify its use. It looked awful pretty, sure, but a Titan outranged it and three or four Titans outgunned it for only a marginal cost increase. A single Mark 3 on the other hand is definitely superior to an equivalent cost in Predators, as it should be, and as the original Mammoth beat out the GDI Medium Tank by a similar margin.
(It's utterly hilarous to me how much the original Mammoths were capable of laying waste in the last GDI mission of Tiberian Sun, they would have stomped a Mark 2 flat, and they don't even have legs.)