Gun-armed armored cars seem like a promising next step, but we should probably have a heavy antitank missile program going. If we can build native-designed surface to air missiles, even bulky and crude ones, it should be doable, even if we have to settle for wire guidance.
I mean, the thing is that even if we make armored cars that can only stand up to 12.7mm and rocket propelled grenades, that's fine. Like, in the post-WW2 world most armored fighting vehicles couldn't stand up to dedicated anti-tank weapons, including the main gun of enemy MBTs. It wasn't until shit like complicated composite armor and ERA became a thing like 30 years later that it was possible to create AFVs with potential immunity to enemy fire.
The important thing for an AFV is not to be immune to enemy fire, but to be able to outmaneuver the enemy and to shoot first as far as I'm concerned. Armor is a nice bonus, but we can't rely on having thick enough or advanced enough armor to be immune to enemy fire right now in part due to our industrial and technological limitations. As a result, I think it's better to not try to be immune to enemy fire but instead to focus on something that fits our needs (mobile, armored, carries big boom, can be transported easily by rail or river, cheap/easy to manufacture) and not get stuck trying to make an uberwaffen like the Germans in WW2.
I basically agree that we need an AFV in the 'armored car' weight class as you describe. And, realistically, need it more pressingly than we need a forty or (God help us) seventy ton tank.
The big problem is that the Victorians run on schizo tech and that this somewhat complicates the picture.
On the one hand they are
literally using significant numbers of T-34 tanks as a mobile element for deep penetration raids where possible, which means that we kiiind of want something mobile on the ground capable of confronting that, including something capable of taking the offensive in the face of that threat if they ever think of parking the tank hull down behind a ridge and letting
us come to
them.
On the other hand their infantry is probably toting shoulder-fired antitank rockets from the Cold War or possibly even
more advanced simply because it's not worth the Russians' trouble to replicate an RPG-2 or whatever bullshit archaeotech Lind would have them using. Aaaaand it's very very possible that the Victorians will get ahead of less primitive Cold War style Russian tanks at any time.
So there's a desire to build tanks capable of engaging the Victorians in a tank battle, and if they stick to T-34-85s
this isn't actually hard, but at the same time any tank we build on that scale may be targeted by Cold War weapons which makes things a lot harder.
In the short term of the next five years, saying "fuckit" and just trying to get an armored car design mass-produced that will let us standardize and replace the hodge-podge of technicals we use at present, plus mounting heavier weapons like 90mm guns that are reliably capable of breaking the armor on their current T-34 force, is probably good enough, I agree.
On the other hand, some day we're going to want to take the offensive, and I think trying to have more heavily protected vehicles will be desirable at that time.
