I've used the small Blazer vanes on some light arrows for shooting 3D in my recurve trying to squeak out a little more horsepower /grin
Sure, the better tuned you are the less fletch needed...but that not the ONLY reason; Bigger fletch helps stabilize your arrow due to minor form flaws too. Heck, I've shot with some of the best stick bow guys in the US....and they may use tiny fletch in competition, all use a decent size feather or vanes when hunting.
Its the same ole thing about hunting vs target shooting....and the reason why even some of the worlds best shooters have made some bad shots on animals. Heck, I was on a hunt decades ago with the IBO World Champ [compound] one year...and he missed a bull that came in to under 30 yds on that hunt. This from a guy that can hit a $.50 cent piece every time in competition at unmarked distances....it happens.
Put 3-4" feathers on that thing and call it a day.