I think ungainly rather than unfit is exactly right. There are several refs around who appear ungainly in their running styles, and Huxtable, Martin and Adock immediately come to mind. There are others who seem to stroll around, take for example Marriner and Kavenagh. However all of these and others are up with play when it really matters, and the only ref who does not come into this category is (imo) Hooper, so I also agree with Hendo in this regard. At the other extreme Mason, Attwell and Woolmer always seem to cover a lot of ground during a game although I don't personally think this makes them better referees.