This. Players develop at different ages also.. Some develop early, while others take longer. Shaw is an example of the early development, while not many really rated M. Keane at age 17-18.. He was nothing more than Will Keane's twin.
Jones is an early bloomer too, I think LvG will give Keane a chance at the back this season though I'm surprised Tyler Blackett made it to the tour ahead of Tom Thorpe (much better defender), only reason I can think of is that Blackett's the only other left footed CB (Evans the other) we have in the team.
Anyway, back to the point.. I think Keane and Jones are two very different defenders, and its not fair compare the two especially since Jones has been playing 1st team football in the prem since the age of 18? Keane's got a lot of talent and I think LvG see's that too.