To be clear, I'm not saying it's OP, I'm just playing devil's advocate. Because it sure as heck is annoying.
It's 36k mass, not 72k. And it completely wrecked ez's eco. A nuke would not have done way more damage, those mexes are too spread out. The Novax killed every single mex not under a shield, at least 200 mass/sec worth of eco and would have been more if they'd all been t3, a nuke would have killed 4 at most.
The "inconvenience" of making shields is fine on a map like Canis; on a map like Seton's... do you know how long it would take to march engies all around and make all those shields? How much power it would take? And still they would die to Novax, it would just take some extra time. Do you really want this game to be about that kind of minutiae?