Hi Kirk.
83 images in the folder total.
I sorted by 'Capture Time', and manual inspection shows that the most photos with the same time is 11.
There is another group of 7 or so with the same time, and then the rest are mostly unique, with few pairs having the same time.
Photos with same time are completely different photos, not photos taken in a high-speed burst.
I acknowledge this is unusual -- these aren't photos I've taken. This is a package of stock photos I received from a Disney "memory maker" package from family vacation, haha. So while I still don't understand the PM rename behavior here, what I've learned is that it doesn't make sense to rename these photos based on date/time since since the date/time on these is meaningless. It's possible there are other oddities with the metadata.
I will choose some other scheme for renaming this particular package of photos. So I don't need to pursue this any further, but happy to provide more info if you'd like to.
A separate question: Last time I purchased PM (version 4.x.x) was in 2012. I had been using 4.6.9 on my previous machine with High Sierra, but I just got a new machine that I'm building up as a clean install (rather than via Mac Migration Assistant). I couldn't get my old 4.6.9 package to install on my new machine, which did not surprise me. I knew I was on borrowed time. Am I eligible for any discount on PM5 based in my 2012 purchase of PM4.x.x? If not, that's fine, I got 6+ years out of my $150 license and it was worth it. I don't mind paying again when my PM5 trial expires, but can't hurt to ask..
-Chris