Why not, Romania, Bulgaria, Croatia, Slovenia Bosnia and Montenegro would all fit right in.
mafe, I think that we here, at least needs to talk honestly and openly. Here we aren`t on BBC or CNN and we don`t determine world`s questions. We are free here. So, shall we? From my side, you will get valuable info, in any case
Firstly. Define to yourself Croatia, Bosnia and Montenegro. Its all about Serbs and `Serbian question`. Those countries are Serbian lands that aren`t Serbian right now for all sorts of reasons but all reasons are due to foreign madding. Competition between religions. Weakening of Serbs and by that Slavic South in general. Etc, etc. Still, there are people (no matter are they Catholic, Orthodox, Muslims or atheists) that wants to be Serbs. Anyway, imagine Poland entering in there (to gain something), ignoring Serbian question. It would be aggression, that won`t have support even from majority of Poles. Not to mention that would such aggression antagonize Poland with Serbians, Czechs, Slovaks, Belorussians and Russians. Do Poland need that? No. Do Slavic world need that? Of course not and that could be final thing that could actually destroy Slavs.
Secondly. Czechs and Slovaks won`t even stay in Visegrad if official Poland continue to provoke Serbia. Even Hungary don`t need Visegrad with antagonized Serbia. Slovenia (small Catholic country of 2 mil. proud Slavs but generally weak and ready to resist to non-Slavs only if Serbs supported them)? No, Slovenia won`t go with Poland if it consider going against Serbia. No, not that they love Serbs passionately but they understand strategy. They knows that `Serbian question` must be resolved and they themselves have problems with Croatia. Slovenian only hope to gain something is to wait for resolution of `Serbian question`. See, Poland can`t offer that to Slovenia, what Serbia can. Plus, Poland can only bring troubles to Slovenia. With Serbs, Slovenians are in equilibrium with Germany and Russia. With Poland, Slovenia actually, don`t exist, if you understand me.
Third. Croatia is German factor. What would official Poland expect here? To side with Croatia against Serbia and to prove its loyalty to Germany? Forget Intermarium in this case. On the long run, forget ....
Fourth. Bulgaria? Ha, that would be some combination. All treachery what Poland can expect from Croatia, also can get from Bulgaria. Just, Croatia is Catholic and Bulgaria is Orthodox. Tell me what betrayal you prefer. Plus, holding Bulgaria by Poland would secure Russian invasion of Poland, while holding Croatia securing another division of Poland. Think about it.
Serbia is not at all strategic to anything Poland wants to do and the idea that it is, is just kind of silly.
Serbia is everything to Poland. Only way out of misery, in strategic, in nay sense. And vice versa, Poland is hope to Serbians. With one slight difference, not only hope. But still, we wait Poland. We prefer Poland. What would Poland, its up to Poles.