Now, your CEU map presents Balkan Zone. How are you going to achieve that unity? Yugo states fought a cruel war which is still remembered.
Take example of Serbian-Hungarian relations. Those relations historically maximally antagonized in turmoil after Turks invaded Europe and Germanic used opportunity to expand, while Serbian and Hungarian states were weakened.
Now, when Serbia strengthen, when dropping German and Austrian influences, Hungarian-Serbian relations consolidate.
See? That is first answer on your dilemma. Sole strengthening of Serbian state, will return things in order on Balkan, in Central Europe, in Europe. There won`t be any kind of invasion by Serbian state. No. Flame of resistance to what is false will burn from within Montenegro, Croatia, Bosnia and Herzegovina. It already happening. Some 60-70% of former Yugoslavia, at least, will return to Serbia.
Then, that consolidated Serbia will extend its hand to Poland, as it happened in past and that is the biggest fear of those who are against Serbia. Strong, pro-Slavic and Slavic-friendly Central Europe. It would be virtual restoration of amber trade route wealth line.
Slovaks and Czechs will follow automatically. East Germany? Depending on deal with Germany. Independence of Lusatian Serbs is immanent. Its minimum. This with Muslim migrants helping same as open promotion of Greater Albania helping here in the region. Also helping rising of appetites of Italian and Hungarian states in case with Adriatic coast. Belarus? Depending on deal with Belarus and Russia. Lithuania? Well, Lithuaninas will be reminded that Serbs were military elite of Polish-Lithuanian Commonwealth. Not reminded in violent way, just reminded where they need to seek their peace.