Actually, I think that it is possible to train all 3 guys. However, it might be a bit difficult and during some weeks you might not get all guys their 48 minutes. Along with that, height can be an issue.
The first guy has problems in DR and PA. If you decide to keep him, I would recommend training both to at least average or respectable for now. After that, I would train OD to proficient.
The second guy has low OD, so he would do better as a big. He already has decent secondaries, so OD might be the only thing you need to worry about at the moment.
The third guy looks good for the most part, and could use a bit more OD and some JS.
If you sell anyone, make it the first guy. His problems may take away from the training of the other 2 players.