Hi,
could it be possible that you have no practical experience of doing any photogrammetry yourself yet?
I mean, some difficulties I can think of off the top of my head are ...
1 the first customer comes along with a chihuahua, the next with a horse - what kind of setup could cope with that disparity in size?
2 hair and fur are so difficult to scan well - have you tried anything at all to get a feel for just how difficult it is?
3 what if a horse gets scared by the camera flash, or the noise of the shutters and bolts off, knocking over and trampling over your cameras?
I could be wrong but if you haven't actually tried any photogrammetry yet, just do some small experiments to get a feel for what is currently possible and what isn't.
The theory looks fine - be prepared to spend X on lots of cameras, and then this will be your magic money-generating machine, no skill needed, just press the button - but in practice there are lots of ways in which photogrammetry falls short of neat and tidy expectations,
andrew