In my opinion, yes it is. It depends on the people of Belarus though if they want to be part of Ruthenia with us and the Rusyns or if they rather revive Great Litwa with Lithuania (as you might know, many Belarussian nationalists like to refer to themselves as Litwins). If they want to join I would welcome them with open arms, if they prefer Great Litwa I'm fine with that too.
As I already explained, I would include Belarus but it depends on Belarussians if they join us or revive Great Litwa or if they prefer to stay in their present day form.
Speaking of potential states and alliances, what would you think of forming an alliance of Baltic and Slavic states, including Czech Republic, Slovakia, Poland, Ukraine, Belarus, Lithuania, Latvia and Estonia? Of course not all mashed into a single state, more something like an alliance based on economic and military cooperation.
Is it identical situation as we have in Poland, where Silesians and Pommeranians (Kaszuby) are all tribes from same root? I would be willing to rename Poland to Lechia, since it would represent Poles, Silesians and Kuszuby.
It's similar situation here, yes.