Usually one doesn’t put reality aside. I would have to go back and reread *Pittburgensis Ruthenorum * to see if the original pastoral provision from the original bull separating the Pittsburgh Exarchate from Philadelphia was explicitly extended. If not, it may only be questionably de jure.
Time is also another significant factor; St. Nicholas was established in the very early 1900s and was involved in the original division of parishes between the two Exarchates. The more recent waves of Greek Catholic refugees and immigrants from the Krizhevci area post-World War II has almost entirely been to UGCC parishes. Particularities of law aside, they went to the parishes they wanted to.
I suppose another argument can be made that those of Galician provenance or descended from the Union of Brest could place themselves in parishes of the Philadelphia Metropolia anyway. In any case I know of no historical complaint from any BCCA hierarch to the UGCC or Rome over this issue, and it is now what it is fifty plus years after the end of World War II.
I don’t advocate putting reality aside - only noting that reality is what it is. (I’m a proponent of allowing Eastern Catholics - and those coming into the Eastern Churches from elsewhere, including the Latin and Protestant Churches - to seek acceptance from and be accepted into - the Eastern or Oriental Catholic Church with which they most identify.) And, as you’ve pointed out, reality in this day and age is that Macedonian Greek-Catholics are more likely to be found among the parishes of the UGCC. It’s perhaps more difficult to define where ethnic Croats might be found and, as you note, the ecclesial choices made by these Greek-Catholics is hardly likely to disturb the Metropolitan Archeparchs of either of our Churches.
Both Ss Peter & Paul in Chicago, now of blessed memory, and St Nicholas in Cleveland were erected canonically around the turn of the century (1902, respectively). Although both were responsive to the canonical jurisdiction of the respective Latin ordinaries, they deemed themselves under the omophor of Krizevci.
Ss Peter & Paul was actually served by a Ukrainian priest, Father Gregory (Chomitzky), of blessed memory, for much of its early existence (1917-24, when he was replaced by a priest sent by the Eparch of Krizevci but appointed to the pastorate by Pittsburgh, and again from 1927-1937). In 1938, the parish requested to be formally accepted into the Exarchate of Pittsburgh. It was and Bishop Basil (Takach), of blessed memory, appointed a priest from Kriveczi to its pastorate.
Ss Peter & Paul Croatian Greek-Catholic Church, Chicago IL
St Nicholas was accepted to the Exarchate about the same time.