The rules suggest that the training will be faster if a player has complementary skills (a good rebounder and inside defender will pick up shotblocking quicker). So that is different from HT.
But the rules also suggest that you train more players than you need at some positions, and trade for the others, which is like HT.
Players in BB are somewhat older. I have had one 18 YO, and mostly 19 YO are the youngest. I don't know how much of an age impact there is for training, there is one, but I don't know if it is as severe as HT. Also the rules mention that there is an height effect on training speed, a big man will pick up inside skills quicker, and a shorter player will pick up outside skills quicker.
There has been a long thread about training speeds, but I didn't really read it. BB may be a little more complex, since training is based on minutes played, and it may difficult to get 48 minutes every week for each trainee, it might make sense to switch training around even when using the same skill (rebounding for C-PF one week, for C-PF-SF others).
My coach is a 5, so I've hesitated when a 9 has been offered, because of the salary, but I might have upgraded a 1 coach. I've left my doctor at 1, and so far I haven't had any injuries that lasted longer than the end of the game. I did upgrade my PR guy.