Okay Trev, about your net situation. I'm basing this on you only having 8 free nets rather than 10. Once you get 10, it'll be a lot easier.
Firstly, given that he's your youngest trainee, I'd have Bennett on, at the very least, two nets, preferrably batting and fielding, although once his concentration gets a bit better, you could probably just change it to two batting nets. Unfortunately, having him on two batting nets then means that one of your 7 remaining trainees has to miss out on a net. I'll just go ahead and say what I'd have each of the others on before actually deciding who gets the short straw.
I'd then have Brewers and Bridges me (haha, still gets me) on either one fitness or one bowling each. Given that they're both good bowlers, respectable stamina would be a good idea, especially with FC coming up (hopefully). If you went with a fitness net, once they did get to respectable, I'd consider changing it to a bowling net for each of them. Carey obviously needs better concentration, so maybe a fielding net would be best off for him. However, like you said, he also needs better stamina, while his batting doesn't stand up with the others. Regardless, if he was getting a net, I'd give him either a fielding net, or maybe a batting net, so that you'd increase his batting along with concentration.
Likewise, Greening needs better concentration to go with his relatively high batting skill, so probably a fielding net. Respectable stamina would also be nice, given his batting skill, so any spare nets could also go to fitness. That said, he seems to be your best bat (from what you've posted, that is), so a batting net might be a good idea instead of fielding, especially since he's one of your younger trainees. You should be aiming at getting him to, at the very, very least, competent concentration and respectable stamina.
For Noon, it depends what you're looking for, a keeper or a batsman. IMO, he needs a keeping net over a batting net, because his keeping is decent, but not excellent, while his secondaries definitely need some improvement. A batting net would be nice as well, but definitely a keeping net. Then we've got Patel, who's much easier, just give him a batting net, cause his stamina and concentration are pretty decent as they are. Finally, Staveley could do with respectable stamina, so a fitness net might be a good idea, though batting wouldn't hurt either.
So basically, I just wrote four paragraphs full of indecision. In short, this would be my net set up if I was in your situation:
Bennett- 1 fielding, 1 batting
Brewers- 1 bowling/stamina (until respectable)
Bridges m- 1 bowling/stamina (until respectable))
Greening- 1 fielding/batting
Noon- 1 keeping (then one extra batting when it's free)
Patel- 1 batting
Staveley- 1 batting/fitness (until respectable)
I've left Carey out, simply because he needs better stamina, batting AND concentration and you don't see to have the available nets, so it might be a good idea to just bat him down the order. Even though I said you should get most of your players up to respectable stamina, the jury's still out on what will cut it next season in FC, and competent will most likely be alright, so I'd probably be tempted to just improve their primaries right now.