Depends who "the commons" are. All human communities migrated from Africa so by your logic I suppose one would have to pinpoint the FIRST migrants to arrive at and hunt/cultivate the land in question to determine ownership.
So in UK it wouldn't be the Anglo-Saxons and it probably wouldn't be the Celts because they migrated across the steppe. Whoever was there before them, we'd need to find them and campaign for them to own the land.
In Scotland it's a little easier, we know that the Scots genocided most of the native Picts, the remnanets of whom are in the west of Scotland, so they get the land I guess.
I have a problem with this as I am not sure humans can rightly be said to own any land. Surely it should be pre-hominids and animals native to that land. I don't think the land should be regarded as 'owned' at all. It all strikes me as a bit Manifest Destiny.
Either way, I respect your viewpoint but I prefer the Marxist way of looking at wealth exchange, production and dialectic materialism as I can understand it better. And to my original point, I don't think Progressivism engages much with socialist politics. I don't hear Progressives talk much about the working classes and the rebuilding and nationalisation of manufacturing heavy industry which would build our GDP. I hear them talk more about matters of hyperindividualism such as identity. I may be listening to the wrong Progressives though.
I do agree that the ground rent industry is a criminal racket, and it's dreadful that the commons were taken to make hunting parks. I am also upset about the Dissolution as the abbeys and land which provided charity to the poor were mostly gifted to Henry VIII cronies. Mind you, before that it all ultimately belonged to Rome so not common ownership.