Old Toad's suggestion to use Smart Albums is probably best.
I tried using the Duplicate finder in the trusted 3rd party app PowerPhotos ($40) with a Library of jpgs from my Nikon. I was then reminded that at Horse Shows I sometimes take pictures of jumping at 10 frames/ second, sometimes faster) so I had lots and lots of similar pictures!

In PowerPhotos you can change some of the requirements for being duplicates, like data and time or file name. But you can't say something like >95% similarity--settings like that would be pretty cool.
On the other hand, PhotoSweeper ($15) has this sort of thing:

which has a "Series of Shots" mode, and you can set the max time interval.
For similar pictures

you can set the level of match. I haven't really used this-- I need to play with it some more…