When the GM practically puts up a neon sign saying "MAKE PORTABLE GATLING GUNS", you follow that advice.
There is no neon sign saying make portable gatling guns. It was one of a laundry list of issues mentioned with our infantry last turn, and by attempting to portray it as simply a matter of PORTABLE GATLING GUNS SIGN you have to ignore the entire litany of problems we face, such as comparative survivability and comparative mobility. Even if this DOES solve the mobile weaponry problem, all it does is make it even, not better than theirs. We cannot narrow enough of these gaps with these revisions to overturn last turn's status quo, much less deal with their new design as well. You cannot oversimplify these facts away.
We can quite possibly lower how much territory we lose this turn, but I am sure that we WILL lose territory this turn. Accordingly, I have voted to button up in hopes of making the losses I see as inevitable this turn hurt less, which will also give us a better base later, especially if we totally hold the South Peaks. Remember, they won pretty handily in the North Peaks.
At the same time though Powder, simply because it cannot bridge all of the gaps in one fell swoop does not mean that it isn't worthwhile. Arguably being able to leverage greater firepower in a more mobile manner would mitigate their defensive advantage as well. As for your concern for only matching them? Well we are at a current disadvantage; outright upending the status quo in multiple areas to an advantage is a tall order. The path of 1000 miles begins with but a single step, after all.
Now as for the other revision... I am torn, really. The Mountaineer could have pretty decent synergy with the portable gatling guns, and possibly serve as a foundation for a take 2 on the uniform; but reinforcing the South Peaks could also be a decent move, with all evidence pointing that they can in fact beat us up in mountains and successfully force a landing... My vote there is very tentative; not solid at all. But in the end?
Fortify the South Peaks: (3) Powder Miner, DGR, Jilladilla
Salviosi Jacks and other defensive measures: (4) Powder Miner, DGR, Taricus, Rockeater
Portable Gatling Guns: (2) NUKE9.13, Jilladilla
ECR-15 'Mountaineer': (1) NUKE9.13
TBC-16 "Doomfire" Tactical Bomber: (1) Taricus
Fortify Harren (1): Rockeater
PRE-POST EDIT (Dammit why do you all have to organize your thoughts faster than me?): Powder, I don't think we've lost our fortification in the Savannah; it's still listed at 2 Entrenchment, we just can't further entrench ourselves in it while Abbera is there.
As for the Jacks.... This is just something that is going to go obsolete, you know? It may have a day or two at the edge of the spotlight; but all they need to do is make their stuff hover higher, or even just 'jump' to render it pointless. It's a dead-end tech, and it's not even one I consider vital to compete in the moment.. Hell; the jacks may even end up more of a hindrance than help! All of our ground vehicles remain pretty darn close to the ground, we don't really have hover vehicles like they do. (I mean, yes the armored sleds hover, but those are pushed around by hand soooo..)