You train specific players to specific skills that fits with there position. No reason for example to train 7'3 C OD. Team training u r using only for FT and stamina. If you train 1 skill all the team, the result will be so poor...
Do NOT listen to Johnny. He is absolutely wrong. With a 7'3" C, OD is a great thing to train because it allows you to be able to run a strong outside defense. If you're running FCP or 1-3-1, wouldn't you want your C to be able to play OD strongly? There is not a good reason to NOT train your C in OD.