The Rusins (Ruthenians) come from the Carpathian Mountains in Poland, Slovakia and the Ukraine. There's lots of blame to go round in that part of the world. The Rusins were dumped on by both the Poles and the Russians, as Poles were by the Russians. Orthodox to begin with, Rusins were so persecuted by the Poles about 500 years ago that they went under Rome (became Greek Catholic, their native church today) to try and stop it. (The home of the Ukrainian Greek Catholic Church, Galicia, was in Poland from the 1300s until the Soviets grabbed it in WWII.) It didn't. (Their crime: not being Polish!) I think it was the 1920s-1930s when Poland persecuted the Orthodox there so much that the saintly Ukrainian Greek Catholic Metropolitan Andrew (Sheptytsky, a Polish count by birth) officially complained. The notion of Slavic brotherhood was unheard of in most of this history; it was a 19th-century Russian idea with a bit of imperial ambition in it. (Like the Austrians who ruled Slovakia and part of Poland invented Ukrainianism as a hedge against the Russians. Ukrainianism = Galicianism.) But given what they went through, no wonder there was a Russophile movement among the Rusins in Poland. The Communists killed that. (The only Russophile Rusins today are Orthodox Slav-Americans, few in number, who think they're Russian: the result of a mix 100 years ago of Russian imperial missionising and the Rusins, spurned by the local Irish RCs, approaching the Russians on their own.) During WWII Rusin Greek Catholic mountaineers fought a guerrilla war against the Soviets and Polish Communists and by the late 1940s lost; the Polish Communists deported them to the USSR or dispersed them in Poland and either burnt down their villages and churches or gave them to the Polish RCs. Rather like the Russian Communists stole all the Ukrainian Catholic churches and gave them to the state Russian Orthodox Church which had been beaten into Soviet submission. Like I said, lots of blame to go round here.
Poland is and ever shall be Roman Rite just as Russia is Byzantine to the bone.