The organization of nano-objects on macroscopic surfaces is a key challenge for the technological improvement and implementation of nanotechnologies. For achieving operational functions, it is required to assemble nano-objects as controllable building blocks in highly ordered superstructures. Here we demonstrate the growth and self-organization of metallic nanowires on surfaces into hexagonal superlattices with tunable characteristics lengths depending of the used stabilizing surfactants. Starting from a reacting mixture containing a Pt(111) substrate, a Co organo-metallic precursor, an amine and an acid dissolved in a solvent, we quantify the structural evolution of superlattices of vertical single-crystalline Co nanowires on Pt using a combined analysis of small angle neutron scattering, transmission and scanning electron microscopies. It is shown the concerted steps of growth and self-organization of the nanowires into a spontaneous 2D hexagonal lattice on Pt, at intervals starting from a few hours of reaction to a highly ordered superlattice at longer times. Furthermore, it is shown that apart from long-chain acid and long chain aliphatic amine pairs used as stabilizers, the combination of a long chain aliphatic and a short aromatic ligand in the synthesis can be also employed for the nanowire superlattices development. Interestingly the possibility to employ different pairs allows quantitative modulation of the nanowire arrays, such as the interwire distance and the packing fraction.