Time Machine drive mismatch with iMacs?

Hello,

Recently rearranged the computer area containing my 27" and 24" iMacs along with three Time Machine HDs. Of course, TMs not labeled and became disconnected.

Due to different layers of dust and mfg. date on TMs, I think I know which goes where. From what I've read, if they are mismatched, worst case is a new file for partitioning.

Guess my question is, will anything blow up?

Thanks,

analog man