The truth is that every players in premier League always find it very easy to adapt to any kind of league especially Bundesliga so if you check very well you will see that all the premier League players that find themselves outside the premier League are always on a better form, while most people believe that Bundesliga players could hardly adapt to the premier League do to how difficult premier League is that's why most most people were thinking that Haaland will not perform very well on Manchester City but however he was able to surprise everyone with his impressive performance and the good records he has created for himself. So actually Harry Kane performance on Bayern Munich was actually expected because he was one of the best player on Tottenham Hotspur before he joined Bayern Munich.
The team Harry Kane comes to is also important. He came to Bayern and Bayern is not an ordinary team. He can easily find the passes and team play he wants at Bayern Munich. He showed similar performances in the Premier League. He has already gotten used to the Bundesliga and I think Bayern has brought in the best striker they can get.
In this case I think this also applies to other players and not just about Kane. We must be aware that when players decide to be at a new club and a new competition then everything will be different when trying to adapt so this is where the players have to start and do well whether their choice is a good choice or it will damage their career.
Kane is a very good player on the other hand he is also used to faster competition so it is indeed a good thing when he comes to the bundesliga (Bayern) where the competition is a little slower especially now that Bayern is the best club in the bundesliga so he is doing very well for Kane.
But that does not mean that only player from EPL club can do this because it all depends on how the fit with the intended club and the initial chemistry that is built.
We can see some failed transfers including perhaps the case of Reina who was signed by Bayern a few seasons ago in the Pep Era. So it doesnt depend on where the previous club is but how the player is because even if he was previously in the EPL but when he cannot build a good chemistry then surely the player will have difficulty at the new club.