The gecko and Iguana are explicitly easy to repair and get parts for, and it is easy to extrapolate to the Lizard as well given they are all part of the reptile series. I agree that faction sameness is an issue, but I doubt having a tank that does not flee from a pistol is overly contributing it to it, especially when 3 of the 4 TAG descriptions talk about how mentally tough they are, "live in fire and spit it", or are used as the vanguard of a boarding party.
Yes, like every other faction, something CB made a concerted effort to do. And you'd expect a TAG that "lives in fire and spits it" would be able to do, or the vanguard of a boarding action secure in the knowledge he is the most heavily armored unit in the combat. By the way, overselling it. An Avatar would be a Queen, an MBT is comparable to a knight even if MO can't take a squallo.