i think you forgot one important think - JS level itself not only DR and PA,HN has impact on wheater the big man is gonna shoot or not. I dont see big differences between high DR and JS - i would pick JS even when more expensive. Dont forget 50% of all shots are jump shots, not inside shots in every single tactic! But that is only my opinion based on my team with little less DR inside (but having 18pts/game against top world teams and i mean top world teams).
I agree with need of good OD for big men, however only when 3-2 Zone playing. C have no big problems with low OD (in like 80%) when playing m2m..
Actually I don't see a Center in your team with 18pts average per game. I do see 2 Power Forwards, of which 'good old' Branislav Drunek averages 18pts per game. But yes I agree that Jumpshot has influence on Centers, but I didn't mention it because the influence is in my opinion less big than the influence of creating a chance (after which jumpshot or inside shot are used) there. If you won't get the ball there the player won't shoot. However when a player has got Jumpshot, the opponnent might be forced to defend him even if he gets further away from the basket. This creates space and more oportunities to create a good chance.
I know you have played against top notch teams, but you have a top notch team yourself, therefore I'm willing to make a small comparison between Drunek and my Bernlef. We are both playing in the I.1 and I think that both I.1 won't differ that much.
Drunek (PF, 248k, JS 12, JR 5, HN 5, PS 4, DR 7, IS 17), has got a shotpercentage of 0,653 and 19,2 points
where my Bernlef (PF, 158k, JS 12, JR 3, HN 9, DR 13, IS 14) is clearly the less shooter with a percentage of 0,484 but averages 23,7 points.
Looking at the minutes both played the points per 48 minutes would probably be about the same, but mine had more chances. Looking at the statistics this is probably because he is the better handler, passer and driver.
I haven't taken things in consideration like tactics, but since your the better team and I play just as much in as outside I think this would not make my point less strong.
This at least shows me I probably should get Bernlef his IS to 17...