[shimarikakari]

I think it's mostly an issue of weight. A field loader weighs about the same as a big ball catcher. If you use both a big ball catcher and a field loader, then that's a certain amount of weight you take away from improving the shooter and the stability of the drive train. Realistically, will you ever have to collect balls using both human players and field loaders? It seems to me that you should use whichever type of loading you can build more effectively, because I doubt that either type of robot will find a shortage of ammo with eighty balls split between the goals and the field.