I would like to convince you to leave in the skirmish between companies if I can. It was to lean to the factor that the floating cities are not a perfect world, even if the whole skirmish was covered up so its a red tape matter (aka never happened on record). It would also mean that should we progress far enough into the story that the war does break out it can give some reasoning as to why the corporations may turn on each other. Also means John has a reason to be so silent, since the fight that cost him his friends never happened on public record, their just down as "KIA" and nothing more.

The armour side is actually pretty thin compared to modern Abrams tanks of 600mm. I didn't want to go too thick or it wouldn't make sense how the thing moves, but accompanied by Chobham armour most ballistics would hurt it but take more than one round to fully punch through unless it was a high AP round from a direct hit. In most cases I'm pretty sure that kind of hit would kill most vehicles, luckily the shape of the frame helps direct a lot of energy away from the chassis instead of absorbing the whole impact. It's not one solid piece either, it's a layer by layer style, so the impacts do get absorbed over the whole plating instead of focused on a single point. It's a whole lot of science stuff that gets complicated, but think of it as jumping into a net, the whole thing shares the strain not just one point. The primary focus is what that armour plating is forged from. Abrams use a type of depleted uranium mesh, but I'm not sure what kind of metals you have in your world for armour.

I've adjusted the height by a few feet and decreased the weight by 10 tonnes, to try and make it more reasonable.

As for the Corporation description, I'll post that below.

Krupp is a very old name in alloy, artillery and munitions production. Dating to over 400 years ago, and one of the most productive corporations during the early 20th century, Krupp has since continued their stable and impressive history of a reliable manufacturer with vast numbers of contracts for private security supplies and new construction materials. Although technically older than Montha, Krupp fell out of favour during the last great war. Economic collapse caused the great industrial giant to recede back into a smaller role, only recently expanding to that which they were before the crisis. While Montha and Krupp are in a contract deal regarding the sales of materials and reactors, Krupp has been striving to produce their own variant of the Monthian Reactor to little success. It has lead to more than one legal battle and a few known under-the-rug scenarios with failed tests, but the company has been able to stay afloat so far. It now manufactures a wide array of Mechanized Suits that are employed in many roles, from industrial lifters to Mobile Artillery.
Krupp has a vision, the future is now.