TIL we can modify the order of our AmiDock icons!
I originally thought I could open the dock.config file as a text file and simply reorder the statements inside. That didn't work because the file is actually some sort of unreadable gobbledeegook.
So I went back to my original disk and poked around to see if there was any mention of this obvious feature we'd all want. Inside an Addendum readme in a changelog there was a short update where if we simply hold down the ALT key, then click the icon you want to move, then click the icon you want to swap it with. Voila! Good to go! (And remember to save the config when you're done.)