There are a couple of correct answers to this question, but having direction in your goals is needed to make an assessment of what the right answer is.
First-off, a good indicator is relative weight of fish caught-of any size-which will tell you if there is a gap or lack of available forage for that size of fish. Thing is, that forage size will have an affect on other predator species of different sizes, so it's a moving target.
The one thing that is nearly impossible is having large numbers of large fish in every species. To get "some" large fish of any one species, you need large numbers of small fish of other species.
I don't think it's over simplifying by saying the lean fish (Low RW) are key to what needs to be changed.
I think to best answer your question, there is no specific time frame that X fish should be removed, it's a measurement of length vs weight that will tell the story and this takes accurate records with accurate equipment to make determinations which is time consuming but doable for anyone who's willing to follow proper recommendations.
With a bit of time you will catch on to having some insight into what you should expect by making each change, which ALWAYS affects 3-4 other things but takes some time to see the results.
Rule #1., Mother nature will continue throwing unexpected curveballs your way-always expect the unexpected so don't be surprised. That's why there are general recommendations and not hard-fast rules.
