<-- huge snip -->

Just for completeness should someone dig this thread up trying to solve an issue...such as a 12 port router....

The kernel's FDT determines the order of detection for built-in interfaces.
Learn how to make them, then don't change it and the interfaces will always come up the same way.

Mask (delete, override with empty) e/udev rules and scripts and use the purpose created 'ifrename' utility.
And don't use SystemD OS..