This is not true. Consider that the SA and FA are distinct. The different dimensions and divergences can not be optimally corrected by a single radially symmetric lens. No matter how long the cheep Chinese modules make the single collimator lenses they are forgoing the opportunity to more accurately correct both axises of the beam. The shame is that full correction and even spatial correction is not difficult and the results are remarkably better. For a given laser source such as a diode or a gas laser there is an inherent quality to the beam (related to the M^2 parameter) when it is generated and no combination of lenses or filters is going to create a silk purse out of a sow's ear, but the right combination can maximize the quality that is present.So in theory one should strive to get as big FL collimator as possible within the required aperture beam width. Generally that's what all (or most) chinese suppliers do: they put long FL lens as a collimator, so long that even FA divergence becomes... 'acceptable', and then don't even bothers correcting it. Nice/cheap approach, however, in the cost of wide beam at aperture (and FA/SA divergence difference)