I've always believed that the CV series is a series about generations of terror. Dracula is defeated, but eventually rises again while a descendant of the Belmont family has to step forth to put him to rest. The whole concept of family lends itself to a timeline and each generation acts as a means of progression.
You CAN have an ambiguous setting retaining the whole family/generational progression, but you have to be crafty regarding how you reference "so-and-so" Belmont is the father of "that guy" Belmont.
For me, it's not relatively hard to follow a timeline as long as you are a stickler for continuity. That's one of the main killers of a timeline. Even Bryan Singer's been called out regarding the X-Men movie timeline and he's said ALL the movies so far are canon, and whatever inconsistencies there are, "just forget about them". The problem here usually lies with writer/directors that don't take much care inserting stories into an existing timeline, hence the clutter, retcons and continuity errors. I think timelines can be done right if you take the timeline into heavy consideration with each additonal story you create. From what I've seen, especially when you get new writers on board, it seems like they are more interested in telling a new story rather than thinking about how they can fit it into an existing world without going against established canon. That's a problem that I'd wish more writers would consider addressing. If you want to write something new, do it for a new world(establish your own world to do as you please), but when writing for an established franchise with an existing canon, you are bound by the rules. You better school yourself in the existing history of the previous stories and school yourself GOOD! There's no excuse. If any layman fanboy can do it, sure as hell someone within the company, getting PAID to do it can as well. Really, I'm pretty hard on this because I hate when stupid retcons are made for the sake of, "Oops, I forgot THIS event happened differently! My bad!!". There's no excuse whatsoever.