I'm quite a fan of Black Tree but the thing to remember about their ranges is there's quite a bit of diversity in the sculpting style.
I've got some of their Dwarves but I was very selective in what packs I chose as I wanted some that were more realistic in appearance and similar in scale/design to the LOTR and Vendel ranges. However, alot of their Dwarves are quite cartoony and somewhat similar to 80s/90s Citadel/Marauder Dwarves. I'm not sure how much this extends to the other races/lines.
I realise this info isn't that useful to your Beastman question but what I will say is you should probably go through their catalogue with a fine tooth comb and pick out the packs which have minis in a similar consistent style for what you're after. Also make sure you look at both the Black Tree Fantasy and Harlequin sections of the site as they both contain some fantastic figures and alot of them could be used together.
Hope this was at least somewhat helpful.