I tihnk the number's that he gave are just an example, but the concept could be used to encourage cross training.
And it shouldn't be 'specific numbers' either (eg: Strong and Strong) - It should be a different way, such as having two skills the same.
So as an example, you could have a player who has the same skill levels for Outside D and Shotblocking for instannce, and , they get a 'bonus' of some kind.
So it could be that the player has OD and SB @ Inept - well they get the bonus. Or it could be Strong and Strong.
Doesn't have to be those 2 skills either, could be something slightly more related. But the concept is not a bad one.