The surname Kowalski is very popular in Poland - you may refer to:
https://polishforums.com/archives/2005-2009/genealogy/kowalski-blacksmith-son-bloke-33629/Regarding the Czarnecki name, it was discussed here:
polishforums.com/genealogy-6/czarnecki-surname-research-23653
I don't know much about Zarembski name (besides the fact that it could have an alternative spelling in Polish, ie. Zarebski or Zarębski; some offices confused these spellings too).