Of course, another (though potentially more costly) solution is a very attractive assistant.
Seriously, given the length and weight of the kit, I still wonder about the bandoleer with a shoulder harness using the monopod, as you've shown. Or, would that be too heavy making you want to lean forward? Then a second body and lens on a BR?
One thing I tried, which worked reasonably well (in a no-stress situation), was to tilt the 200-400 lens downwards and have a strap I could tighten between the base of the tilhead on the monopod and the left shoulderstrap of the bandoleer. With the other lens on a BR, it worked reasonably well. But you have to stand quite still when you do it. Maybe combine it with a flexible strap to the backside of the shoulder strap could work.
5DIII, 1DX, 8-15/4L, 16-35 f4L IS, 24-70/2.8L II, 70-200/2.8L IS II, 70-300/4-5.6L IS, 200-400/4L IS 1.4x, Zeiss 15/2.8, 17/4L TS-E, Zeiss 21/2.8, 24/3.5L TS-E II, Sigma 35/1.4 Art, Zeiss Otus 55/1.4, 85/1.2L II, 100/2.8L IS Macro, Zeiss 135/2, 600/4L IS II