How about coming up with a greatest XI such that you don't choose 2 batsmen (or 2 bowlers who played in the same era). You can list your all rounder as a batsman or a bowler. Wicket keeper can be from any era.
( You can have your own definition of era. Mine is divide the entire cricketing history into periods of 15 years. 1990-2005, 75-90, 60-75, 45-60, 30-45, 15-30,...and a player can be chosen in an era if he played 50% of his matches in that period).
Also, it would be interesting to come up with a XI containing players that got "underhyped" by the media or fans in that era because of the presence of other greats.
Make sure that your favorite batsmen/bowlers (*) makes one of the lists
First XI: Hobbs(c), Gavaskar, Bradman, Tendulkar, Walcott, Sobers, Knott, Marshall*, Ambrose, Trueman, Barnes.
Underrated XI: Sutcliffe, Ponsford, Dravid*, Barrington, May, Border (c), Boucher, S Pollock*, Underwood, Tyson, Bill Bowes.