It's been a long time (15 + years) since I owner a Blad. I remember it worked in EV units whereas the fstop and shutter speed were locked together. I remember pulling back a ring that uncoupled the speed/aperture and it could be set offset for half stops. Geeez I having trouble placing it all, but am confident that 1/2 stops were available.
That's correct. The C lenses do offer half stops. You pull back gently on a little tab on the right side of the lens (at least it's on the right side of my SWC) and then you can adjust the aperture relative to the shutter speed in 1/2 stop increments. It's a bit slow to get used to. At least it was for me. You don't have completely independent control over shutter speeds and f stops.
You decide what your exposure needs to be in EV. Then you turn the aperture and shutter speed together, the shutter speed getting faster as the aperture closes down. Once you get used to it, it's a very nice system, since you can try different aperture settings and the shutter speed is automatically changed to maintain the same exposure. My only objection is that it would have been nice to be able to easily defeat the locked rings for bracketing exposure. Perhaps they did on the newer lenses? I have no idea as I only have the one 35 year old SWC.