I have used batch rename sequences for decades and only recently have had this problem Nikon camera names are such as 900_0271.MOV. After I have rough edited day folders and kept what I want and added metadata, I runumber according to my system. for example I would do a folder where the 1st number of a series would be 9005001. I would put text as 9005, and if the total number is less than 995 in the folder, I would choose the sequence to be 001, and they would all be sequentially numbered. but recently I found that .mov files were split into a .mov and a .nef with the same number. the ,mov shows a low value of maybe 20MB and the .nef is large like the size of the original move in hundreds of megabytes of over a gig. Metadta is usually all gone. In one case I went to the backup and found the files with old numbers and matched by position in relation to adjacent nefs and the size matched and copied each individually and recovered. However next time this happened I found that I had mistakenlly not backed up and so at least 11 moves are unplayable and unrecoverable. There could be more that I didn't notice since Bridge no longer shows video thumbnails for later cameras.