Pump up your Soldier recruit numbers from your governor.
I've gotten plenty of nice GR gear from freefolk settlements, including tanks. Every time you claim one, you get free stuff. They tend not to survive very long due to their low numbers, eventually a lucky hit takes them out.
Human wave tactics are your best bet.
But with the SHQ issue, you're probably better off just starting over and expanding quicker. Pump out those soldiers, make many formations, draft your city's populace until you cover the map with your troops. Well, at least for the first few years. Then you'll be the one sporting the GR stuff, since you'll be taking every population center on the map. And then you can fiddle with the logistics issues of keeping them all fed (Supply Dumps, Truck Depots, nationalizing your starting private transportation center, building roads, building farms, building water mines if needed).
Seems like they found them somehow or leftover from the before times. I had a minor with all walkers at game start once.
That was probably a Rogue AI. They spawn with all GR Walkers. They won't attack until you've gained some tech, just surround them so they can't wander in and take over.
< Message edited by EuchreJack -- 9/17/2020 11:29:56 PM >