everybody in the world (sorry for oversimplification) is learning English not Polish - these dark-skinned doctors that you probably know or have seen in Poland all educated here and this is how they obtained their Polish -
I met a Jordanian Doctor, educated in Poland, who had worked in a Polish hospital in Gdansk for 10 years, now he is back in Jordan working as a tour operator. It is all about the money.
If Poland has a shortage of Doctors and nurses, someone has to fill the void.
you need to know the language well to be a doctor in a given country, wouldn't you agree
If you are a trained specialist, English will do.