educational philosophies in Poland and English speaking countries are very different
Very much so. I probably shouldn't say the place, but I know of one school where there's tremendous conflict between Polish and international parents over education. It's not just the obvious things (non-stop testing, grading and giving homework), but also over the curriculum - the Polish parents want more and more theoretical knowledge and less time spent on practical activities, while international parents want more practical and useful activities and less emphasis on dry knowledge.
The school is a mess as a result.
Another problem is when one or two nationalities dominate - so you end up with a school that might be theoretically English speaking, but in reality, the school reflects the home culture of the dominant nationality. There's one Turkish school like that - I'll see if I can dig up the rulebook for teachers for you, as it contained quite a few nutjob things that you'd never see in a Polish school.
The only genuinely good international schools in Poland are the ones run according to the philosophy of the country that they claim to represent. I can think of three, maybe four in the whole of Poland that work that way and are successful.