In some cases, yeah, that's a far throw from a single force under Brussels control.
I suppose I'm very much of the view that a lot of things are unnecessarily duplicated in the EU - for instance, although there's now the "one-stop" border on the Croatian border with other EU countries, there's still police from both Slovenia and Croatia at every crossing. It would make much more sense if there was a single common border guard, and it would allow Croatian resources to be deployed more effectively elsewhere (especially on the porous Bosnian border).
At the same time, I'd like to see countries such as Germany using their resources to help defend the Baltic borders - it's not exactly a big secret that Russia can move people in/out of the EU pretty freely there.
And most of all, it would be nice to have a common EU border guard so that practices such as France not even bothering to control American flights (used to happen frequently at CDG) could be stamped out, or the Greeks refusing any and all offers of help.
how many Finnish departments there are in Poland
There are departments in Poznań, Gdańsk, Warsaw, Krakow and possibly more. It's just madness - to me, I don't see much reason to have so many when none of the departments are particularly good. But again - I see the competition being with other EU countries, not just within Poland.