Wikipedia says that people often mistake Oberlanders for Yekkes because of their similar customs. I’m not saying whether or not that statement has any weight, but it does at least show that the OP of this thread isn’t the first person to draw the comparison.
Nachum: There were Jews following the Rema before the Oberlanders existed, wouldn’t they be Yekkes? I don’t see how you could assert that Oberlander minhag predates Yekkishe minhag unless we’re just defining it differently.