Thanks for creating this post! It encouraged me to go back and do the research myself. I don't have an easy way to collate by shots, as we do a separate LR catalog per event, and I shoot my studio headshot sessions tethered into Capture One. That said, I use text files to plan out my packing, so I collated the numbers from those files. Note that these numbers represent how many times an item went into the bag, not necessarily how many times it got used.

26 1Dx
8 5D3
11 5D4
41 5DsR

(The 5DsR is my all-around workhorse. It goes every time unless I have a compelling reason to replace it with the 5D4 for a blend of resolution and higher ISO, the 1Dx for weather and responsiveness, etc. The 5D3 was my studio backup until we added the 5D4, and we do have two 1Dx so there's not a lot of granularity into whether that was 26 separate events or times when both went.)

4 11-24
15 14/2.8
16 16-35/4IS
31 24-70
5 24-105
3 24/1.4 (rented)
31 35/1.4
12 50/1.2
3 70-200/2.8IS
9 70-200/4
2 70-200/4IS
5 70-300L
16 85/1.2
3 100-400II
9 100 Macro
19 135/2
1 600/4 (rented)
2 1.4x TC (rented)

(I'm honestly surprised the 16-35/4IS didn't beat the 24-70 here. I've found it to be a very versatile walkaround on the 5DsR, as the resolution allows me to crop to somewhere around the 70mm equivalent, so essentially I get a 16-70. I've been doing a lot more shooting with primes now that we've added them to our lineup, and I do tend to take the 5DsR and primes when we go see artists at Jazz Alley.)