Blocking 2 Positions:
Trains SB @ 2-3 weeks
Trains ID @ 7-8 weeks
Trains RB @ 7-8 weeks
ID two Positions:
Trains ID @ 2-3 weeks
Trains DV @ 7-8 weeks
Trains IS @ 7-8 weeks
Trains SB @ 7-8 weeks
One and One:
Forwards:
Trains DV @ 1.8 weeks
Trains HN @ 2.3 weeks
Trains IS @ 4-5 weeks
Trains JS @ 4-5 weeks
You see the difference?
My experience is that SB is affected quite strongly by height (more than ID for sure), so a really tall player will progress quite fast -- close to the pop rate of driving for forwards. But then again, that's just my nonscientific opinion.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."