Do you need a bigger gun than 145mm?
Remember your iron triangle
- Mobility
- Firepower
- Survivability / Armor
Want more of another? Get rid of another.
145mm APFSDS is probably good enough to take out harden targets.
145mm HESH can probably delete buildings
I can’t afford to lose these tanks, sure I could make more, but that means the crew is probably dead, which means I need to train replacements, which takes time, money and effort. I don’t have that time in the event of an interstellar conflict, which means it needs to be highly survivable, to minimize losses, and it needs to be mobile, to not get hit. Hovertanks are bad, because more moving parts means it can break down easier. Reliability over all else, and Im not putting a nuclear reactor onto a tank, since that’s a glassing incident waiting to happen