So, at least one village and one town has been named after a noble family Jordan.
Does that really surprise you? Way back then, the name itself would indicate that this person was an owner of that village, most likely of noble heritage himself or warrior class who has been given the ownership of this particular place. That’s as far back in time as documentation allowed Janusz Stankiewicz to trace this clan. The family fortune or lack of it throughout history is irrelevant, so is establishment of any settlements by this clan or acquisitions of new estates which they may have renamed. This is where the written documentation for the bearers of this name begins in Poland.
Question is, where the Jordanowski name really came from? A name of a peasant, an artisan, a Jew from any of those villages/towns, an illegitimate child of one of those noble Jordans? Someone related by trade to the network of Jordan Gardens?
You would have to trace the origins of the name Jordan as it is found in the Bible, but naming a town or village for some Biblical place is not that unusual in Poland as well as other countries so good luck with that. As for what branch of this family the person who asked this question came from requires tracing his own ancestors as far back as he can, that’s where the fun begins. He could find his family is not related to that clan at all but bears the name coincidently as they adapted it themselves being from one of the places you mentioned. Of course he could be any of those and only he could answer that question by doing the research on his ancestors but that’s not what he asked for, is it?