I don't really have a preference regarding this matter. I could work with either PD, PF or PA as the second parameter to decide on ties. PD seems to be most generally used one across different sports, so there would be nothing wrong about using this. Though, if we would like to follow another path, then I would be up to reward the best defense in these situations too!
Thanks for your opinion, LennuK., and I'm glad to hear you´re open to different ways of handling this situation!
Yes, PD is mostly used around real leagues in my experience/understanding as well. And what's one positive side of it, current way of handling things (league table calculations) do give a direct indication of this without making any additional calculations.
(Yes, if the team stats would be made available on a regular basis, that would also "automatically" provide us PA and PF valiues, but for instance now I'm running late in creating such stats, so PD is something that's already always "automatically" available).