But Exum played more games than Neto last year (42 vs. 37) and 3 minutes per game more than Neto.

I would say Neto can be good insurance in the situation where one of your guards gets in foul trouble or has a bad game. But if one of your guards gets injured and you need Neto for extended minutes then chances are (or were last year) that Neto would end up injured too. I think part of that is just that Neto started off training camp out with a hamstring injury and probably had to nurse that the whole season. Maybe next year he'll be more durable.