...Also, while the titular ship of Star Trek:Enterprise looks completely unlike her Vulcan counterparts, she was supposedly designed with Vulcan help. For all we know, the traditional "Starfleet look" of saucer hulls is actually a Vulcan invention, while two nacelles is a generic way to get warp (also popular with e.g. Klingons, Romulans and Orions) and rarely worth swapping for Vulcan or Ferengi style configurations.
Alternately, we could claim that Archer's Enterprise was built with Andorian or Tellarite know-how, specifically so that Earthlings could thumb their noses at Vulcans. That would be something of a conspiracy theory, though, as Archer himself didn't appear versed in Andorians or Tellarites. But choose some other race eager to trade with the primitive Earthlings in the early 22nd century, exchanging worthless baubles such as starship designs for priceless treasures from the natives such as local booze.
Personally, though, I rather disliked the ENT idea that ships of the classic Starfleet silhouette would have been introduced before the Federation was. I'd much rather have seen them as the result of cooperation between different cultures. With their multiple haphazardly connected components, they do look as if designed by a committee!
Timo Saloniemi