The Bae et al paper linked in that paragraph (https://iopscience.iop.org/article/10.3847/2041-8213/ab46b0 https://iopscience.iop.org/article/10.3847/2041-8213/a

The Bae et al paper linked in that paragraph (https://iopscience.iop.org/article/10.3847/2041-8213/ab46b0 https://iopscience.iop.org/article/10.3847/2041-8213/ab46b0) (note Bae is cited second on OP paper) actually has quite a bit more to do with the way planets settle into orbits, based on study of this same system. As a fellow layman I haven't read it in detail but it looks fascinating, will check it out later. These are really interesting papers and full of pics and diagrams, although the math is beyond me.