::::::Well then Le Sage's model would have infinite range, not finite range.  Quoting from the article "Le Sage proposed that the corpuscles were minuscule relative to their separation; that their motions were rectilinear; that they rarely if ever interacted;..." which suggests he envisioned a collisionless gas.  As is well known a collisionless gas and a perfect fluid's observable behavior is identical and would not experience any finite range limitations.  If you have a finite range limit you must have an diffusive process in play.  Either way, the actual interactive mean free path is irrelevant, unless you have some sort inelastic component acting during particle to particle collisions, thus you're back to diffusivity. Thus perhap what needs quantification is the question Does Le Sage's theory have a finite range? Certainly the general modeled process most certainly can, an I expect does, since nothing in nature is perfectly perfect.  However, why I expect is irrelevant, but if there is any finite range limitation it will be due solely such diffusive effects.