If it's a potential unlock, I've seen it spammed. I've faced everything from Helo's to tanks to mech infantry. Even the dreaded supply truck rush!!!
Hellfire Kiowa spam was annoying but they burn through ammo so quickly. Pact flame tank spam can work on close on maps(they get 20 total flame tanks)
Ultimately spam is ineffective. Against a competent commander flat out spam requires an Extreme amount of points advantage to break a line.
You both get the same number of points, even if you reserve some for AA, he won't have much of an edge. The key to dealing with it is positioning and fluidity. To break you he has to concentrate all his units on a single point/small area. You can respond by sacrificing those front line troops in a delay(infantry won't escape, kill what you can. Faster units and more expensive units should get to a safer place. Your units bought you time to setup a defense, don't squander it.
There's little difference between the types of rush, whether it drives or flies you'll deal with it in the same general way. The only difference will be that you want large fire lines for your SAMs or close in engagements for your AAA. Dealing with ground vehicles depends on your opening composition.
Ultimately everyone will see that spam is entirely chance based, and the chance is that your opponent is an idiot. Education is the best thing to better the community
EDIT: Also, you should always hide your command vehicle at spawn. Just do it in the deployment phase, not like it takes any time. And if you don't have decent AA at your spawn you're asking to lose. It's just something you buy every game, just in case.
My command vehicle comes with me, most starting sectors are worth 1 point and there's usually a reinforcement point worth 2 closer to the front. The only valuable thing in my starting sector is my FOB. While I prefer not to lose it, I've proven in the past I can manage without it. It just requires more caution.