Just going to weigh in here as someone who switched back to the 'camcorder' form factor with the FS5 (mark 2) after using mirrorless for years.
The traditional camcorder form factor with its side controls is noticeably easier to use on a tripod. I never once used the viewfinder on my FS5 and would generally want to use a third party EVF if I went that route - the one on the camera is simply not that good and would be very difficult to judge focus on, and the positioning of the EVF I find fairly awkward for hand-holding (you'd have to lift the camera up to your face. Generally with a small camera like this, I'd prefer to brace the camera against my chest, which feels more secure and results in less arm strain. Using a C70 style body in a similar way seems like it would cause the controls to be squished up against the operator.
I know some folks on here are a bit dismissive of client perception, but I do a fair bit of corporate (not glamorous but hey) and doc work. Client perception is super important to my bottom line and I've had clients specifically call out the video form factor in a positive way, saying things like "oh, what did that camera cost" and "That looks a lot better than my mirrorless that I have at home". It's not (although specs aside I much prefer the SLOG 2 our of the FS5m2 than the A7s in an unquantifiable sort of way), but that perception goes a long way to justifying my day rate and the money that I spent on the camera.
I miss WAY fewer shots with the FS5 than I did with an A7s. Don't underestimate the value of internal ND where the colour shift is compensated for automatically, being able to use large-capacity batteries that don't require swapping out every hour etc etc. It makes shooting on primes much more viable in a quick moving situation and removing colour casts from an ND (any ND) filter from log footage in post is a huge pain, if it's even possible with the limited codecs on these cameras.
All that being said, I'm sure mirrorless ergonomics have come a long way in the last few years, so take my comparison to an aging Sony model with a grain of salt. Happy shooting folks.