You do realise that Pilsudki's plan miserably failed and caused the destruction of the II RP?
The Second Republic did fall, but Nazi Germany and Soviet Russia were its destroyers. If you think Piłsudski's plan for Slavic unity was the main cause of the Second Republic's fall then you are very deluded.
You mean the plan which featured Lithuania (not Slavic), Latvia (not Slavic), Estonia (not Slavic), Finland (not Slavic), Belarus, Ukraine, Hungary (not Slavic), Romania (not Slavic), Yugoslavia (only partly Slavic) and Czechoslovakia? More non-Slavic nations than Slavic ones?
Yes I mean that plan which proposed unifying several Slavic states along with several other Non-Slavic states. It was thus a plan for Slavic unity. I never said it was a plan for exclusively Slavic unity.
And did not feature by far the largest Slavic nation?
Yes, and Piłsudski had good reasons for this omission. It was not a plan for absolute Slavic unity but a plan for Slavic unity nonetheless.