You're getting circular errors because you've got:
A. Formulae to determine ranks, with the possibility of ties.
B. Tiebreaker formulae depending on A, i.e. you calculate tiebreaks only if the ranks in A <=5 (the number of prizes).
So if you try to feed back
B into
A to break the ties, you'll get circular errors.
Looking at your tiebreak formulae (for the first time, sorry - I've been avoid digging into all your formulae) it looks like you're just looking for lowest scores counting back hole by hole from the 18th? In which case, why not calculate tiebreaks for
all players on this basis?
The highlighted cells illustrate, for a hypothetical 9 holes, the countback for Players C, E, F and G. The rankings are fully resolved by the time we count back to round 6, and hence don't change before the final results in B17:B26.
In my Post#38, I provided formulae to resolve the tiebreaks, assuming the tiebreak rankings were in $CJ$27:$CJ$72 (for Gross) and $DC$27:$DC$72 (for Net). If you calculate tiebreaks ranks for all players, and put them in these cells, my formulae should work? And if (as it appears?) the countback is the same for Gross and Net, you'll only need the
one set, rather than two, of tiebreak ranks.