For a funfly, having the horizontal directly behind the wing is almost mandatory with a tube fuselage.
That's where it is on my StickIt and Ricochet, Femto...
The very good flying "Hots" series also places the horizontal in line with the wing.
Above or below the wing is OK for looks mostly.
For a plane which isn't going in any one direction for any length of time, I doubt it really matters.