I really don't know how you can come to the conclusion that the SA conference is the weakest. I'd say the OP has more legitimacy since the arguments against his are based largely on conjecture and perception.
2015 the NZ conference has dominated the likes of which you have to go some way back. SA clearly some distance behind but just as clearly ahead of the Aus conference as a whole even if the margins aren't as pronounced.
Now 2014 is different. There the SA conference was certainly the weakest performing as a whole but then 2013 the SA conference was the best performing of all three.
The only single stat that backs up your perception is points difference against every other stat that paints a different picture. Also, I'd back wins and log points over points differential which is the easiest one to get distorted by blow-out results. Not that any of this really matters but still.
The good thing for me is that rumors are the Stormers are getting more quality players back than we are losing for next year and the Lions look to reatin their current crop. But we'll have to wait and see. On the other side the bulls and Sharks are set to lose a lot of key players.
I came to that conclusion because while the Aus table is lop sided both the Tah's and Brumbies were contenders. And now we have 4 teams left and none are from South Africa I think my conclusion is pretty accurate.
"2013 the SA conference was the best performing of all three"
Really? Sounds very definite. ok lets have a look
Competition points total:
AU 231
NZ 240
SA 239
hmmmmm... not really, slight edge to NZ. lets look at total PD
AU -32
NZ +23
SA +9
no NZ has a slight edge here as well
ok what happened post season?
AU Brumbies 4th reds 5th, brumbies promoted to 3rd because of conference system.
NZ Chiefs qualified top of the table, Crusaders effectively 3rd, so 2 NZ teams in the top 3. Crusaders pushed to 4th because of the conference system.
SA Bulls 2nd Cheetahs 6th
No NZ advantage here as well...
Finals Rugby?
AU won 2 finals games
NZ won 3 finals games
SA won 0 finals games
AU vs NZ final, no SA team
NZ team the chiefs crowned champions....
Conculsion overall, close competition but NZ clearly the strongest conference. not much separating AU & SA, SA slightly better regular season and AU doing better post season thanks to the Brumbies.
Ok WTF are you talking about stormer? I know I am bias at times (ok settle down! lol) but c'mon