Yes, lizardmen are based off of things we have. No, that does not make ripping something directly out of somebody else's work make us look any better in the eyes of the enemy, or anyone else, which is my primary complaint with lizardmen. Although I'd also appreciate something with more interesting features, i.e., stone-eating rock-armored whatever-the-heck-you-might-want-to-make-them-look-like. Well, also it's not REALLY a reptile if it's not cold-blooded, and none of our stuff is going to be cold-blooded, because we live in a darn plane of ice and wind, and for SOME REASON I don't think a reptile would appreciate it here.
I'm not convinced of the logic you are presenting here. Dinosaurs are huge reptiles, which gives them GREAT shock-trooper value...and also makes them a huge target for projectile weaponry and magic. Combined arms is usually better than being completely reliant on one particular thing, yes. However, we can make use of combined arms far better if we don't have to pay for weapons (Since the goal of the Thevryn is to produce our weapons and other equipment for us, as well as constructing anything we might want to be built later). Back to the logic, dinosaurs are liable to be hugely expensive as well....and I'm not arguing for godtier anything anyway, at least not yet (There may come a time when it's a good plan to have ridiculous things of some sort available...._, soooooo?