There was a successful glider, the Schemp Hirth SHK in the 1970s with a V-tail (a few are still around today). One of the greatest problems with the SHK was explaining to others how the tail worked.
Stick back - both tails up. Rudder left - both tails left. Rudder left, stick back simultaneously - the surfaces move, well....in a most confusing manner. The explanation was best ended at this point: "The glider will probably spin"