My Rolleiflex T is also very prone to flare if the sun hits the front lens, though it has a Tessar. From my experience, the only thing that will reduce flare dramatically is a good shade. Some years ago Iīve made a "scientific" test on slide film, using some of my Rollei lenses, single- and multicoated, with and without shades, while the sun was shining on the front lenses in a 45° angle. The result was the following: Multicoating did not really improve resistance to flare by much. Neither did the original lens shade for the 80mm Planar, though it did help a little. The by far best result was with the 250mm lens, compendium shade and mask for this lens.
I think a Hasselblad will be more flare-resistant than a Rollei TLR, but only because there are larger shades available. The 100-250mm shade is quite large. I think a 100/3,5 CF together with this shade will reduce flare in your pictures a lot. But when used without a shade, I donīt think there will be an overwhelming difference to the Rollei. Problem with TLRs is that you canīt use huge shades since they would interfere with the viewing lens. The zoom you mentioned can only be used with the 200 or 2000 Series, but from what Iīve read, it is pretty good.