Hellraiser motorized can move field guns my heaviest motorized platoon is 35.5 tons with 2 AC-20’s
While that might be
Motorized for "movement" those are
Field Gun Platoons and not at all the same thing.
Optional Rules, Custom Platoons, etc etc. You didn't mention any of that.
Now all that said.......
IDK, you might be able to still use a Karnov.
I'd have to check the rules for sling loaded Cargo but I think it can match it's weight, so 30 tons of guns to go with 6 for the MotorScooterBoyz.