It is a little bit hard to focus on exactly what you are getting at ... I am a 'by ear' player so my approach is to know the tune before I start to learn it. Not that I can't read well enough, but
this has the advantage of not spending time on music that doesn't appeal. This seems obvious ... why would I want to play music I don't like?
Once I know the tune I can quickly get it 'under my fingers', and then I can start to refine the fingering as I practice it. There may be (almost certainly will be) many refinements to the fingering before I am practicing a final version. Thus I am not 'locked into' a final version until I'm satisfied it's as good as I can get it. Even then I may change the right hand.
Long story short, for me learning a new piece is knowing the tune and getting it onto the guitar ... polishing is a work in progress, what musicianship is all about.
1929 Francisco Simplicio
1997 Manuel Contreras Doble tapa