  In this study we address the question of the thermal description of
collisions of classical clusters in the framework of classical N-body dynamics.
We compare the results of systems in central collisions and those of
thermalised systems with the same sizes and with the same available energies.
The comparisons are made on size distributions, on total multiplicities
distributions and on IMF (N>3) multiplicities distributions. These
distributions are found identical for available energies per particle below the
energy of the least bound particle of the total system. They are notably
different for higher available energies. These results may put a new light on
the standard explanation for fragment formation in N-body collisions.
