it's time to annoy the forum again with my seperation of evenly matched 50+ batsmen and <25 bowlers by who can add value with the other disciplines, like what happens in the real world when selecting real teams. it will annoy the proletariat even more when i say mcgrath is the goat but he doesn't make this team.
hobbs
hutton
bradman
sachin
sobers
kallis
gilchrist
imran
hadlee
marshall
warne
viv and wasim/davidson quite close to this team. viv because i think his strike rate given the license to come in at #5 or #6 would be funny and cruel, and the latter two for that handy left arm angle.
Very practical and pragmatic playing 11.
If you are picking a team to actually play a game you do need to factor in having a good 5th and more than decent 6th bowling option. Equally important at least 2 of the bowlers should be competent with the bat. I don't think though that you have to factor in batting for the no. 11 batsman; of you are relying on your no. 11 to win a match consistently you have other problems.
What I will say though is equally important and constantly overlooked in the composition of these teams is the importance of having 3 superb slip fielders and someone with experience in the guĺy.
Not minimizing the importance of same, but the greatest teams in history lacked all rounders but both had renowned cordons. Basically all i'm saying is that it should be factored in.
Additionally So dam should also be boosted over Imram due to the added variety.
In such a team though, I would probably bat Sobers at 5 and leave 5th bowler duties to Kallis, who whilst isn't the batsman Viv is, he outclasses him at slip in addition to his bowling value. As Flem also indicated below Hammond should also be in consideration, but there would only be room for one of them in my squad and I guess it woukd come down to who was the better all round cricketer. Hammond having the advantage re batting and in the slips while Kallis was the more willing and capable 5th bowler. That would be an interesting poll.
My squad by the way (using your premise), with alternatives included next to the original pick.
Sir Leonard Hutton
Sir Jack Hobbs / Sunil Gavaskar
Sir Donald Bradman
Sachin Tendulkar
Sir Garfield Sobers
Jacques Kallis / Sir I.V.A. Richards
Adam Gilchrist / Allan Knott
Sir Richard Hadlee / Glenn McGrath
Wasim Akram
Malcolm Marshall
Shane Warne / Muttiah Muralitharan
Also trying to put forward a balanced team with regards to era and country representation. Hence if was going to include Hammond for Kallis, would swap Gavaskar for Hobbs, and yes Hutton is my undisputed no. 1 opener.