It doesn't need adjustments at all. Everyone knows the dwarf will suck compared to the giant due to the difference in height. And a few inches in height away from ideal aren't going to matter depending on the skills of the player. Look at 6'4 Barkley playing POWER FORWARD, Dennis the Menace 6'9 and one of the best rebounders and interior defenders of all time. As for giants vs little guys supposedly having an advantage, 6'7 DeJuan Blair with no knees absolutely destroyed 7'3 Thabeet. Dwight Howard 6'10 kills Big Z 7'3. Everyone in he league killed Shawn Bradley 7"5.
As for big little men, Magic Johnson, LeBron, Dirk Nowitski and Kevin Durant debunk that theory.
The training aspect is only to make it more realistic to actual player heights. If you train an athlete like Dirk(6'11) or Durant(6'9) in shooting and guard skills all their life they will play a little man's position. Same thing with guys like Blair, Barkley, Rodman, Tisdale. If you train a guy timing, and hw to use his strength to rebound and defend, he will be in a big man's position.
These guys are exceptions to the rule, but it's absurd your complaining about it considering they are exceptions to the rule in BB too.