Origins of family names Kubś, Wiak and Gordon

Greetings,
I am french but my mother's side of the family is almost entirely of polish descent.

One of my great-grandfather was named Stanisław Kubś, born in Sieradz in 1894 of Jan Kubś and Marianna Skoczylas. I think his parents were from Siemkowice in Pajęczno but I'm not so sure. I've seen several writings for this name (Kubś, Kubsz, Kupś or Kupsz...) but they all seem to come from the german Kubsch ou Kupsch. I haven't been able to find anything on the signification of that name. Does it mean that his paternal ancestors were of german descent, or may have the name simply have come from a nickname or a place ?

On the other hand, my other great-grandfather was named Władysław Wiak and was born on the other side of Poland, in Końskowola near Puławy (Lubelskie). His parents Tomasz Wiak and Antonina Piskorska came from the small village of Baranów, and I've found that the name Wiak seemed to hail almost exclusively from the south-east of Poland and most noticeably the region of Baranów. However the variants Viak, Vjak and Vják are also found in Slovakia, Hungary and northern Croatia. Could that be a surname of hungarian origin ?

Lastly, there is also the case of my great-great-great-grandmother Jadwiga Gordon who was born circa 1817 in northern Kuyavia-Pomerania. I have found that it was noticeably a jewish surname in north-eastern Poland and Lithuania, but I haven't been able to find anything that could point to anything other than roman catholicism in her family.

Could you please help me with those names ?

Thanks in advance

Gordon is clearly Scottish.

Unless it's Gordoń ;)

Can be. Obviously not Polish.

Apparently some representatives of Scottish Clan Gordon came to Poland in the 17th century (according to Wiki ). They were Catholic.
There were a lot of Scottish immigrants to Poland back then.
The same wiki page says the name was often used by Jewish families.
Another source claims it comes from the first name Gordian known in Poland since the 13th century.

Good point.

As you're also aware, there's plenty of Celtic admixture in much of Poland over the earlier centuries, particularly around the area of Krakow, according to Wiki.

I have never met those surnames but they are used in Poland, indeed.

e.g., Tomasz Gordon from Bydgoszcz
pl.linkedin.com/in/tomaszgordon