Backup of multiple cards creates a mess

WD External Drives My Passport Wireless
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I use separate cards. In fact, the cameras were used at the same time (different angles). The cards are all 64GB SanDisk, new models. The folders created on the drive showed the card ID, but the files were mixed.
There was another issue, since I had to clear one of the cards overnight, that the second day backup didn’t cover all files as they had the same names as the previous day’s files.
Again, what I want is a full backup, no intervention, and I don’t care of files are backed up more than once. I want to know that the backup of a card on a specific point in time is an image of the card at the time, with no reference to any other backup. Really, anything else doesn’t work for me.