Well, the producers have stated that the KElvin is supposed to represent TOS and the Enterprise etc represents 'New Ultra modern Starfleet'.
Im guessing it was a clever decision on the costume departments part to dress the female Kelvin officers as, in The Cage (original pilot) the female officers wore the same tops and trousers as the male officers, the only difference being the collars of the female officers. Roddenberrys idea of untiy and equallity.
In TOS, the second pilot ep, Where no Mna has Gone Before, the female officers again wore the same as the male officers. It was the Corbomite Manouver that introduced Theiss's classic mini skirt uniforms. They were in TOS since then.
So you can look at it that way. The Kelvin is The Cage, the Enterprise is TOS.
On a costuming level anyway.
"Course your not,your not scared of anything. Box falls out the sky, man falls out of box, man eats fish custard. Look at you, just sittin' there,you know what i think? Must be helluva scary crack in your wall" - The Doctor