Personally, I think there is a real mirror situation going on.
For Rotary's, the Big name was Victa, then Rover, and then a varied assortment of brands ranging in success from Masport to Mowfast.
While over in the world of "Real" mowers, you have SB up front and Atco quite big too, followed by a similar assortment of brands from Qualcast to Royal Enfield.
SB attempted to infiltrate the Rotary's with only a little success (More so later on toward the Brigs Powered 520's and 720's) and Victa Tried at the reels with the Imperial, and later the Turf-master (now a name used on Rotary)
There were others who tried to cross the Bridge, Atco has thrown out the odd rotary, and Austral Villiers hit both marks, and on the professional side, Toro, and I believe at one point Husqvarna have produced both.
Of course the best bridging seen of the rotary gap in my mind is Rover-Scott Bonnar, combined, you get a fair slice of both pies!