Just gonna jump in here and say that I like to keep Poser models 70,000 and under. I usually don't go over 50,000 to be honest but there's been one model where I did. Anyway, the point is, most of the extra detail can and should be handled with texture maps (displacement, diffuse, normal, whatever).  If you have Mudbox and/or ZBrush then you're ahead of the game and can generate those fairly easy. You'll also want to take your mapping/modeling approach on a case by case basis when dealing with unique critters.

Before you get hot and heavy in the character creation realm though, I'd suggest running through some general anatomy books and check to see that your edge flow roughly flows with the muscles you're trying to convey. It will help in adding to the believability of the model. I noticed your minotaur's abdomen to crotch area was a bit short and lacked detail, while the chest was overly pronounced. Step back and think about the character you're making as you're working, think about how it would need to move and in what ways it may live.  If you hit a nice poly count, while keeping the model in the realm of believable fantasy, you'll have an easier sell of it I think, as the model would fit in more scenes.

Good example of form follows function (which is really what I was hinting at): I once was asked my opinion of a deer-like demon creature. It had these really long tusks jutting from its cheek area going past the snout. Problem with that, as cool as it looked, the animal could never exist. It'd die of starvation because its tusks got in the way of eating. So in that case, the form hindered the function.  Just one more thing to think about as you model.

I really hope you get the opportunity to explore the world of model making. It's a blast and very addictive. Feel free to jump in the 3D Modeling forum (shameless plug) if you have questions/need help.

-Teyon.