Best practice/advice for organizing parent company constituent accounts

Hi, I am curious to hear from fellow BB members on your take for inputting/organizing parent company accounts.

Essentially, we have multiple donor groups from a single company (perhaps multiple departments) in which we've entered each group as a separate constituent record. Additionally, we have multiple franchise locations under the same larger corporation with separate constituent accounts. Anyone have advice on how you handle situations similar to this without a ton of duplication or unnecessary extra constituent records? Or is it best to leave everyone separate?

Thank you for any advice you have!