If there's a large difference between batting and an minuscule difference between keeping skills, I really wouldn't care that Crossy is the better technician. The other would offer more to the team. I take Berry's word with a grain of salt, because we all know what he thinks of Gilly's keeping, in spite of his good record. Being seen as the better keeper doesn't necessarily mean a thing in practical terms.
However, I do see your point and seeing as there is no way a 19 year old is going to play every game he is available for, it would make sense to use him in one dayers where it's more valuable.