You are mis-remembering, including bosses Demon Souls had around 70 enemy types, Dark Souls had around 117 and Dark Souls 2 has around 150. All of them are about equally guilty of doing the whole, Enemy X, Enemy X with bow, Enemey X with shield, etc. Though Dark Souls seems to be the biggest offender there.
I think the number of bosses in Dark Souls 2 sort of worked against it, the sheer number took the gloss of the better (either in terms of visual impact or mechanics) ones, I suppose if you count only bosses with an "intro" as "proper" bosses and the other as mid-bosses it looks a bit better.