Is it me or were there quite a few instances of "Someone else by the name X came up with the exact same theory at the exact same time, but they called it Y"?
Yes. This is fairly common in the sciences, because all the good people always know the important problems in their field and are constantly trying to figure out how to tackle them. Then, when a new technique is discovered (perhaps in a slightly unrelated area), it will quickly be tried on these hard problems to see if it helps. Sometimes it does.
That happened quite a bit during the Cold War: many discoveries were simultaneously made in the U.S. and in the U.S.S.R., but they ended up being named after the American scientist (mostly). Fortunately, in some cases, discoveries share the names of the Western and the Soviet scientists who made them.