We had Yugoslavia, for southern Slavic people. Didn’t work out.
Also, instead of returning to our root slavic religion, we got atheism. Without any form of religion, people can not feel that deep bond. Especially Slavic people, who are naturaly very religious.
Yugoslavia was a mistake, but not for reasons you might think.
In most Slavic countries, it is customary to slay and eat a pig on certain holidays, like Christmas and our Slava.
In the US you kill turkeys for Thanksgiving. How different is that compared to other "sacrifices"?
Perun is a "pseudo" God, as much as Zeus was a pseudo God.
And if they are pseudo gods, then Jesus Christ is a pseudo God, too.
Gods exist as long as people believe in them.
Many Slavs feel the same.