Due to historical circumstances, Polish (Polani) ethnicity can only be understand as meta-ethnicity to Gorals, Lemkos, Silesians, Lusatians, etc, same as Serbian ethnicity coming as even older meta-ethnicity to all of them and to Polani themselves.
Why do you think old Polish Kings gave name of `Szczerbiec` to their holly sword that had purpose to unite under their rule? Sarmatism is nothing but Serbism and name of Serbs was first and original ethnic name for all Slavs.