Right? Would it be too hard to make a unified construction system?
The answer, of course, is no. I've done it with Excel--with a system that can make a wheelchair to a dump truck to a RenLeg grav tank--so it can be done.
Of course, it helps if your various subsystems, from armor to ammo and everything else, makes reasonable sense. The BTU is a little bit unreasonable in that regard.
As a design, I lack the understanding of the core conceits to truly appreciate it. But is has a lot of firepower, mobility, and protection for its size. I mean, better than or at least equal to BattleMechs nearly three times its mass. Which is a problem, as I see it. But that is not specifically your fault or problem, Liam.