Yeah. I bet you could manufacture tens of thousands of AT mines for the same price as one of these mecha units with all of its accessories and whatnot. These betas seemed to be blindly charging forward, so they would have happily stomped into a minefield. The mechas were carrying 30mm autocannons, if memory serves, which means a simple and cheap 50mm gun would have been highly effective and quite cheap even to leave behind when retreating. But most of all they should have used indirect fire in the form of heavy artillery and rocket launchers all the time. You can shell targets accurately from tens of kilometers away, that is, from distances far greater than a land based laser cannon can achieve because of its need of a direct line of fire. So, there's actually little need to engage these dull beasts eye to eye, until the remains reach the last line of defense. All you'd need would be some brave individuals hidden in line of sight to give the target coordinates, unless you wanted to randomly bombard them.

But then again, this is a mecha series, so who am I kidding? I didn't actually expect anything like that, but I sure expected the veterans to fight better than the girls and the betas to be much more fearsome.