You're being a purist, and there is nothing wrong with that. I wanted to add Turning Japanese by NOFX (a cover) but the guitarists wanted to cover the original by The Vapours. We discussed what they liked about the Vapurs version (the bass runs on the chorus and solo) and what I didn't like about that version (the tempo). So I learned the chorus and solo runs from The Vapours original version, but we played it at a much faster tempo. Everyone happy
I'm in a good position in that I put my current cover band together so the bass player always gets a say. I just find it important to choose the moment to have that say, and not do it too often
Good luck.