Perhaps I did grasp what you said, but it is just that I consider that you have got it wrong.
As far as I can see, SAFC now has 21 Over-21 years olds in the squad (including Coates and Matthews). Without moving players on (and there can be no guarantee of this being actually achieved) and if the aforementioned are 'squad players' and not to be included within the 5-6 the top quality players required by Advocaat, then SAFC will not be able to bring in the anticipated number of top quality players.
Your suggestion that the natural and logical order of things is for SAFC to fill its basket with the players for whom there is no competition and to defer pursuit of 'the quality' until later. That seems to be a perverse logic to me. The sensible thing to do would seem to be to go out and act swiftly and decisively to secure 'the quality' before the competition is allowed to build. Otherwise the identified 'quality' may be lured to other clubs and locations. This seems particularly logical to me, given the recognised difficulty of getting players to join us because of our geographic location. Conversely, if there is less competition for the services of the 'squaddies' and presumably also a greater range of choice, then their recruitment could be safely deferred until the end of the process
I would accept that there has not been a great deal of movement to date. However, off the top of my head, I can think of a few players who might fall into the 'could effect major change' category. So, for example Holtby has left Spurs for Hamburg, Podolski has joined Galatasaray from Arsenal (what a demonstration of ambition that would have been), Ings and Richards moving on free transfers (yes this would involve big salaries being paid to the players but the overall costs of such deals being affordable because there would be no fees), Ayew to Swansea and Mings to Bournemouth (If you are going to recruit a young centre back, why not get one who can also cover the notoriously difficult left back spot ?) are others deals done that could hae improved SAFC. Additionally there are also several prospective deals, not least of which is the proposed move of Wijnaldum to Newcastle.
I hope this helps.
Well done with learning the calendar, now how about stretching yourself with an explanation as to the relevance of this point ?
see above