Not really. Maybe for Poland and Lithuania but beyond that it wasn't. Pilsudski was far too ambitious when making the plan.
Not the right place to discuss this, but with some luck and few different decisions (without obstruction from Dmowski and his pals) there was a chance to create an ukrainian state. Not to mention that during the peace talks Soviets offered Poland almost all of Belorussia (with Minsk)...
Ironically, Lithuania would be the hardest to sway to join some kind of union of federation. The status of Wilno and fear of polish influence were the main obstacles...
Back to ideas - I'd love to see some events about German-Russian talks before 1941. When Molotov demanded Bulgaria, Finnland while Hitler offered him acces to tripartite pact and british India...