Maybe the next major patch should have adjustments made to the mammoth... specifically it's upgrade
I would suggest the upgrade should be applicable against anti-infantry and anti-tank barriers, with the Mammoth being slightly resistant to the anti-tank barriers.
A more complicated idea for the upgrade is this: Make the Mammoth act like a Venom but ground based. It can still run over walls and anti-unit barriers, but it will attempt to run over infantry and even if it acquires a valid target. It will keep moving forward, endangering it to other anti-vehicle units. The Venom is unique in the sense it doesn't stop moving, even if it manages to find a valid target. While Venoms can't be used to destroy structures, Mammoths in this theoretical buffed upgrade should be able to crush base structures in the same way as they will do for walls.
Mammoth tanks are iconic to the point they are one of the most powerful units available in the original C&C. Tiberium Alliance's Mammoth Tanks are inferior to that of either C&C95 or C&C3, it looks like a small dog to those big muscle dogs.