didn't had poland also teams who started in first division?
Yes, we have (or had) ;-)
And it's hard to fight against these teams. Because even weak manager in higher division still can develop team faster than good manager in lower division. But please compare these two situations. You were in top-16 in Your country in season 3 (in fact even in top-12, because You were never relegated). And finally in season season 16 (13 seasons later) You finished in top-1. So it means You needed over than one season to overtake one opponent who was over You. (Opponents under You aren't so dangerous becasue they have less incomes, so it isn't very hard to beat them and to keep advantage, maybe 4 of them are dangerous, because only 4 teams are promoted to 1st league in season). And compare to other B3 member from Poland, who started in season 4. He needed to beat many opponents and to make 3 promotions to finally to be in 1st league in season 11. And after hard job from this moment he had... still 15 opponents to overtake to play in B3 ;-)
In previous season there was big debate about comparison between big and small countries in B3. But it isn't so important. The most important thing is how many dangerous opponents You need to beat to be in 1st league, and after that how many dangerous opponents You need to beat to win trophy in Your country.
I don't want to start new debate. But I only want to say, that schedule has very small importance in comparision to other factors.