Thank you and other friends who are really helpful and giving thorough answers so that newbies become familiar and enjoy the game as much as you guys do.
Out of the skills you mention, Pressure and Jump Range are one-positions skills, which means the maximum training effect is realized when you select one position to train and make sure 3 guys play 48 minutes at said position. For JR, this position is SG, and for Pressure it's PG. It's significantly faster to train all skills that have their 100% effect as one-position that way.
I understand that in order to train NT players or fabulous players for competitive teams one position training is vital, but what about new teams who care more about training revenue? Isn't it more economical to train 2 positions until I finish my arena (14K, 6K, 500, 50)?
I'm not sure it's the best idea to train handling since HA trains as part of the driving regimen (if you choose driving for forwards, you also train JS and IS that way).
By driving regimen, do you mean One on One? Are you telling me that to improve handling it's best to train one on one for two positions (forwards)?