I think in general it is ‘depends’
- what the player’s goals are
- what kind of challenges are occurring in the repertoire in question
- what the player’s skill level is in relation to those challenges
- sounds silly but: how much the player enjoys repeating the same thing over and over…and over
Tommo is referring to getting specific elements of picking together, and it sounds like your brother was speaking super generally. I think it’s hard to generalize that much and still be useful, because it ‘depends’ on the specifics above.
For a hobbyist, enjoyment is a very serious factor, because you don’t want to hate playing guitar, or not feel satisfied with what your’e working on. Personally I get super bored playing the same thing for more than a week at most but I have students that want to keep coming back to one tune for months.
A big factor with this question is the ‘point of diminishing returns’ ; at a certain point the thing isn’t going to improve much unless you’re really reworking your approach, or maybe it’s just a tune that’s too difficult for that moment. I think if you’re diligently practicing something for a week straight and no real improvement, it’s probably time to either move on or break elements down even smaller.
My .02 from the ‘teacher’s lounge’