I've always wondered why there was more damage on the Enterprise in Star Trek III than was shown in Star Trek II. Clearly, there's more damage shown in ST III where Khan & Reliant didn't even touch her so I'm wondering how that happened.
It's meant to be the same battle damage. Artistic license, like Kylo Ren's scar moving an inch between movies.
Amusingly, if the old DC Comics from that time positing a whole epic range of adventures taking place between II & III could be taken as canon (it isn’t), that’s explained by it being from an entirely different later incident, where a pon farr-maddened Saavik attacked the Enterprise with a small ship.
