Counterpoint: Skaven technology and Doomspheres work just fine. As has been previously espoused by the QM, Warhammer technology is a little fuzzy on technicalities.
Doomspheres aren't manned and tend to explode when properly functioning... getting to reuse them without a rebuild is lucky. They keep the engineering core in the field quite busy.
Skaven technology tend to explode and not having to rebuild them after each use is lucky. Skaven really, really don't care if other Skaven die using their own tech. Skaven tech uses warp stone/magic/warp stone/a complete disregard for the operator safety/warp stone/trial and error costing huge amounts of Skaven lives to get the results the do.
Freddy cares if his troops die (specifically) from using his state issued equipment. So having the tank crew die after every shot is a major design failure for him.
The problems with TC tanks are:
-Recoil is still a thing: There is nowhere for the recoil of the TC to go except through the tank itself. The techs to handle the this level of recoil aren't yet a thing. Cannons in universe and reality have a percent chance to explode that increases with low maintenance levels.
-Bombards, like TC take forever to load: We are not talking about breach loaders with premade shells here. We are talking about
muzzle loaded bombards. Those things are an ogre and half long. Average around 8 foot tall are standard ogres... which means 12 feet in length or more.
-The
steamtanks themselves aren't that long so you'd need remove the boiler to make room inside... which means your tank is going nowhere. That means sticking the TC on the top of the tank. This is an engineering nightmare of awkward center of mass, balance issues on turns, re-engineering the drive mechanism not to break from the recoil, and it being a fixed position gun. Seriously, the tank moves not gun to aim. Making these guns turn sideways will flip the tank. Making it be able to angle upwards for ballistic arc range means pushing not only backward, but downwards. Engineering nightmare.
-The biggest flaw is that even if you can overcome all that... your still dealing with a one shot weapon. The tank having to constantly retreat to fire again makes them spend most of their time near useless. Loading them takes infrastructure or an another specialize vehicle.
Basically near useless for the price of construction. Better design include making:
-A a solid ram tank with a fort on top full of swivel guns and hand cannons/archers Basically, infantry fighting vehicle/APC.
-Ram tank with nozzles all over it to steam/burn everyone around it. Swivel steam/flame turret on top to medium range and anti-everything in that general direction over there gun.
-Go wacky and make yourself a
flail tank.
-Make it a truck for hauling cannons around.
-Make yourself more soup tanks.
Even the originals used steam pressure cannons to fire cannons on steam tanks. Muzzle loaded, big bore, main guns aren't useful in close quarters more than once. The only real solution to this issue is making the steam tank big enough to soak the recoil and at that point your talking about making it so heavy it can't move. Tech level issues. If you want a fast mobile TC... get a rhino-thing and an ogre to operate the ironblaster as per normal. He still has to stop to reload.