Way, way too much kit IMO. Its not weight or even physical clutter that will be the issue, but brain clutter. You will have too many options and choices, resulting in less immersion into 'the zone'.
I'd keep the 645z as the core kit (most lenses), with Canon in support and overing the long end. Leave the 1D X at home, bring the very able 7D II (if you need amazing high ISO the 645Z can cover) with 100-400 II and a wide zoom, like 24-70.
If you have or will buy a metabones, the A7R body only can come to augment the Canon kit and have another lens attached and ready to rock, but if its only for a 35mm walkaround, I would leave it at home, for sure. If its worth photographing, I suspect you will get out the big gun 645z!
As for the 645Z, I'd probably also drop the 55mm DA and go for the 45-85 zoom for more flexibility. Add a few teles and you are set. If either kit dies, you can get thru fine on the other kit. If not, you can keep your 645z on one side for the more purposeful and closer shots and the Eos rig with appropriate lens attached for fast action and long reach. Simple.