I'm a bit confused because you just asked why is RR/GH/SS worse than RR/GH/VV, then said why you think RR/GH/VV is better, but...
I assume this is all based on Kine's spreadsheet maths rather than actual parses, so presumably doesn't take into account factors like gaining TP between fights from Regain. Either way from what I can see from the numbers on the last page, RR/GH/VV is indeed the best DD combination outside of Apocalypse.
Just had another look and perhaps you were looking at the top post? Further down there's the numbers for RR/GH/SS and RR/GH/VV
Lacking AoA, VV is second best option. Third atma combined with RR+VV:
SS: 259.133 (267.289 if uncapped)
Very close, though SS pulls well ahead if crit damage is now uncapped.
Also, RR+GH+SS: 255.574 (265.668 if uncapped), so very close to the top damage atma, not counting Apocolypse.
I think, ignore the 'uncapped' numbers because they were talking about if crit damage was no longer capped at 50%, but it is. But yes, VV should definitely outdo SS, mainly because you don't actually get the full bonus of the crit damage from SS due to it being capped. Also, mileage varies depending on if you have Victory Smite, being higher STR mod you'll get a bigger bonus on Smite from VV than you will on Ascetic's.
That said, I don't have VV, and I don't have Smite either, but regardless I do like the RR/GH/SS combination due to the extra HP too. Obviously it depends on what you're fighting, if you're the main tank etc.
Obviously the maths can't take into account counter rate, TP gained in downtime, and general survivability, so it comes down to personal preference really. But yes, mathematically speaking RR/GH/VV should be your best option in terms of DD without Apocalypse. Parsing may prove slightly differently because of the above factors but presumably when you're geared for such high DD you need to take survivability into account too.
A question of my own: How worthwhile is it to boost these days? I seem to remember this being mentioned somewhere but don't remember an exact answer. With such high attack in Abyssea I wonder if it's that beneficial for the delay it causes. Further to that, if Boost is not useful does this make Taurine Cesti a less appealing option, or does the Boost enhancement make a difference to Boosting being worthwhile.