I think your TBs are plenty enough to cover for a steel bumper.
For comparison: I am running the same 25.5mm AHC TBs and I have just a additional pieces installed:
- Ironman steel bumper
- Warn 12000lb winch with synthetic rope
- Dual batteries
- Slee front armor plate
- WKOR steel sliders
- Gamiviti full-length steel rack
- More towards the rear
- 40G LRA tank
- ARB steel bumper with dual swing outs
- steel Tundra 18" spare with 35" wheel
- ARB single drawer
There's prolly other stuff I am not recalling right now, but the point I am trying to make is that the OEM AHC bars seem to hold all of this wait just fine. I just checked my AHC pressures (with temp sensor unplugged) and I have 6.0 mPa front and 2.1 rear (ignore the rear for a moment).
For reference: Ironman TBs are 32.5 mm and Toyota LC TBs are 29.0 mm wide.