Loken has a dog collar for the Christmas season, for other seasons, and his regulation CCI blue collar. I used to break nails on the split rings while moving the tags until I realized I could use a locking S-biner to attach them.
Put all the dog tags on one loop of the S-biner, then connect the other side to the collar. The lock bar is turned to prevent the S-biner from accidentally falling off.
To switch to another collar, turn the bar to unlock, remove the S-biner, and attach to the new collar.
Locking S-biners are two for five dollars. I expect you can find a use for the second one. I got my locking S-biners at REI.