From my experience, One on One for guards trains 3 Skills with same speed, DV, HN and JS... My player Omar Krasnič popped once in all these 3 Skills, then I trained something else, Pressure, I think, and then after two weeks of One on One, he popped in all 3 Skills again... And he's 23...
I think in this one and half year I trained JS once or twice, I'm constantly rotating between One on One, Outside Shooting, Pressure and Passing, and I have 3 players with prominent JS (all start from respectable or lower), I have one strong (rookie, started from average) and one mediocre JS (bought him this season, started from awful... So, if you don't train JS at all, and constantly train One on One, you'll get JS pop every 3-4 wees... I think I trained Pressure the most, and I have only one player prominent in OD... Plus 2 proficient, 1 respectable and 1 average (he was pitiful when I started)...
And I think you really train faster when rotating training, for example, my player Miško Tuponja had 19 pops in 22 weeks, so almost 1 pop per week... So I would never stick to one training more then 2 weeks in a row...
Since I have time, and you need informations, I'll post here my training (trainer 8-10, always PG/SG training) and Miško's pops:
Week 1, Outside Shooting, no pops
Week 2, Outside Shooting, JR - inept
Week 3, Passing (entire team), no pops
Week 4, Outside Shooting, no pops
Week 5, Jump Shot, JS - respectable
Week 6, Pressure, OD - awful
Week 7, Outside Shooting, no pops
Week 8, Passing, PS - strong
Week 9, Pressure, DV - respectable
Week 10, Pressure, OD - inept
Week 11, One on One, no pops
Week 12, One on One, JS - strong, HN - strong, DV - strong
Week 13, Pressure, OD - mediocre, ID - mediocre
Week 14, Outside Shooting, JR - mediocre
Week 15, One on One, no pops
Week 16, One on One, JS - proficient, DV - proficient
Week 17, Outside Shooting, no pops
Week 18, Passing, HN - proficient
Week 19, One on One, no pops
Week 20, Pressure, OD - average
Week 21, One on One, JS - prominent, DV - prominent
Week 22, Passing, HN - prominent
Well, as you can see, rotating is the key :) And to mention, he's 20...