anchoring two or more surfaces to a fuselage is only possible when the surfaces are sufficiently staggered so that they don't share any plane transverse to the fuselage. this limitation is a pure consequence of the meshing technique. when meshing a fuselage, each anchored lifting surface is assigned to a longitudinal chunk of fuselage that is meshed apart, so that the number of longitudinal panels in that longitudinal band matches the number of chord-wise panels of the wing. this method has been represented in the picture here beside.