[MENTION=79064]MMHS[/MENTION]
The basic story is this.
Test 1: Pakistan loses defending 198
Test 2: Pakistan wins
Test 3: Pakistan loses defending 160 in a Test where the scores were 157, 183, 186 and finally 161-5.
I know that you cant see this, but in both the first and third match, Pakistan would have won if:
EITHER they had scored an extra 30 runs across the two innings,
OR their leg-spinner had managed to take enough wickets in the Fourth Innings.
Part of my current scepticism about Yasir Shah stems from this series.
Equally, in those 3 Tests there was only one innings out of twelve which produced a score greater than 340. Which is why I believe that Pakistans best chance is a low scoring series - especially as Mickey Arthur was the South African coach in that series!
No, PAK won't have won with 130 extra runs (I add 100 more), if Afridi had replaced Kaneria or Azhar/Razzak replacing Asif, Sami, Nazir, Shoaib - because SAF would have posted 400+ then in their 1st innings.
The fundamental blunder that you are making in your assumption is that bowling quality (particularly spin bowling) is flat and any spinner is replaceable by other one - which is not the case. I put it other way - had those changes been made, say Afridi for Kaneria, PAK would have defended far less than 198 & 160 in 4th innings despite whatever extra Afridi scores with bat.
That 2nd Test was won by a brilliant innings from a batsman, not from tail contribution. Before that, one spell of Shoaib where he blew SAF's middle order in 8 balls and SAF's tail couldn't recover from that collapse. For a check - in that 2nd Test, 4 PAK bowlers scored in only innings they batted were 10, 4, 1 & 7 .... and the last 3 guys took 18 of the 20 wickets. In same game SAF's 4 bowlers contribution with bat in 2nd innings were 36, 23*, 0, 18. It never happens that tail has bailed you out of trouble without much contribution from proper batsmen. They can indeed be handy if they can bat a bit, but not at the compromise of bowling - then the balance is distorted.
Test is a specialists game - everyone has to perform his role. It's a flawed logic that you compromise on bowling for batting depth - in that regard you shouldn't play any bowler and pack XI with 6 batsmen and 5 all-rounders : 25 X 5 X 2 = 250 extra runs that should win you every Test. I am surprised that after so many years in cricket and I do know you study this game lot, why this basic fundamental is still confusing you? We argued here lot about the same regarding Maxwell & Lyon in AUS's combination; Nawaz vs Zulfiquar Babar .... latest one is Shadab vs Yasir.
It's no rocket science that if your No. 8 can contribute 29 with bat, it's definitely better than 6, BUT provided that the bowling strength isn't compromised. I'll always say that Shakib & Miraz should play every Test for BD, but that's for their added strength with bat, not for bating ability. I have written here many times that our other Offie Naeem (a 18 years old kid, brilliant prospect) should replace Miraz if he can out bowl him, regardless of respective batting as I don't want 2 offies in XI. Similarly Moeen is a vital cog for English success because he is their best Offie available who happens to average 35 with bat. ENG won recent Series in SRL for Moeen's all-round ability and one of the main reasons being the selection of that specialist SLAO spinner; in fact ENG dropped Curren from last 2 Tests, I believe to keep 3 spinners.
Your problem is, you put it as a formula and expect things to happen to fit your combination. What Mahmood or Razzak - if available I'll say bring Imran & Intekhab to bat at 7 & 8 ......... but you are saying that Shdab & Fahim should play at 7 & 8 - and by their batting position, they should contribute like Imran & Intekhab with bat, then with ball!!!!
I explained this with another game between these 2 sides at Durban - PAK was missing Wasim & Inzi and last 4 wickets were Mushi, Waquar, Shoiab, Fazle Akbar; led by a make shift captain Sohail. Yet, they won that Test because of the bowlers picking wickets for lower cost than SAF - obviously Mahmood's 1st innings & Saeed's 2nd innings century was instrumental, but still it fetched only ~475 as match total. And, to your surprise, Mushi with his 9 wickets won MoM.
It's a specialist's game and PAK's only chance here is to out bowl SAF, for that they need 4 strike bowlers on absolute bowling merit. Yes, we can debate on, if Yasir should play at Highlands or not, and I personally am not sure if Yasir should play had Abbas been available, as bowling picks should be on horses for courses basis, but compromising on striking ability will be suicidal for PAK.
By the way, my apologies for not wishing you. Belated, but better late than never : Merry Christmas, and best wishes for the new year.