I can see why you picked Benaud but IMO I don’t think you can pick any players who retired pre 1970/1980. India were basically glorified minnows, and very few players before that even have a chance of making an All Time India XI. As such, those players who retired before that, although may have great records against India, it’s not the same India and thus remain somewhat untested, especially as you said this would be against an All Time XI - so you’d be playing Sehwag, Sachin, Dravid, Laxman (Kohli) and co.
This current India team, apart from a couple of players, aren’t as good against spin so if Benaud was playing active India XI that would be more reasonable.
I think the only realistic spinner options are Murali or Saqlain. You have to hope the pace attack does something, or might as well a complete random wild card part time spinner and hope everyone gets out with silky mistakes, or one of those once in a lifetime style performances like Michael Clarke’s.