I'm just thinking out loud here, so please bear with me.
I'm not sure I totally buy the idea that our forebears were not aware of how "Americanization" can affect the propagation of the faith. My wife's maternal great-grandfather, Pietro Sartori, immigrated to the US in 1909 and spent the rest of his life being immensely proud of being an American and a Roman Catholic. Her paternal great-grandfather, Julian Balakier, did much the same in 1906. They were both very Italian and Polish, respectively, but they managed to assimilate their strong ethnic pride into a great American pride and managed to pass their faith along to their progeny. Out of their descendants, which number over 100, I can probably count on one hand the number who don't go to church at all, and on both hands those who don't go every Sunday but still identify themselves as Catholics.
Both families managed to maintain strong ethnic traditions and practices, yet also remained fully American. I think this is one area in which the Catholic Church trumps the Orthodox time and time again. While there are exceptions (most notably the bruhaha of the closing of an historically Polish parish in Mt. Lebanon, PA (google it) a couple years ago), historically ethnic Catholic parishes evolve more organically and with far less consternation than the Orthodox ones I've seen.
Take, for example, the recent immigration of thousands of Filipino families into Baltimore over the past 50 years. In recent years, an historically Polish parish has taken to celebrating Santa Nino festivals due to the large number of Filipino immigrants that now attend that particular parish, yet it still has not lost its Polish character at all and you'll find Filipinos at the area Polish Festival polkaing alongside the Poles, thanks in large part to the welcome these immigrants found at their church and among the Polish-Americans, many of whom had immigrant parents themselves.
As I said, there are exceptions, but, on the whole, one does not find these ethnic squabbles amongst Ethnic-American Catholic parishes when the demographics change.
I'm not trying to be triumphalist, but rather making an observation and putting it out for discussion.