AK -
My advice would be to pick a strength . . . and then train in the opposite direction. For example, try to get some inside players that are strong enough to play PF/C for two seasons; then draft a couple guards who you can focus your training on for two seasons. At the end of that two seasons, either sell the the guards for cash or keep them as your guards and switch to training bigs for a couple seasons.
I have found that the key to BB is having one area of strength on my team . . . then focusing my training on another area. That way I have a strength to turn to when I need to win a game . . . but my team is ALWAYS getting better because I am training areas where I don't have strong players.
I know that this is 'easier said than done' at first . . . but be patient and keep moving with a plan. The most damaging thing you can do is try to train too many players in a season. That is the best way to get several players minimally better, and no players significantly better. The MOST players you can train during a single season is 5 (and that is EXTREMELY rare). To do that, you would need to find 5 players that are young enough (younger than 22) with decent enough outside defense and passing so you could train guards or forwards 1v1 all season. But I would NOT recommend that for your team right now.
GL