The use of positions for the light constituent quarks is not exactly unproblematic in the description of hadrons.

The lightest, and most famous, quarks are the up quark and down quark.

However, considering that the light quarks are also produced in gluon fusion processes, one expects increased production of all hadrons.

It is an accidental consequence of the small mass of the three lightest quarks.

They are composed of three light quarks, at least one of which is a strange quark, which makes them strange baryons.

Is there something I'm missing, perhaps a difference in some sort of presumed internal structure between that of light quarks and of heavy quarks?

In this study the baryon had one heavy and two light quarks.

The local term plays no more role for the description of the hadrons with the light current quarks:

His calculation showed that these contributions lead to an interaction between light quarks at low energies not present in the normal theory.

This is not so for the light quarks (u, d, s).