I don't see how that's a stretch really. In the Thor movies, the Asgardians didn't arise out of the Norse culture. They already existed, and the Norse people just worshiped them as gods because of how powerful they were. And there aren't exactly a lot of paintings from way back then depicting Norse gods -- Heimdall in particular is one of the least fleshed out of their pantheon, despite his importance, due to large pieces of lore simply missing or lost over time.
The problem is that you have to cast real people to play what are essentially aliens from another realm, so they're going to look like races from earth. Unless you CGI the entire cast of Asgardians to make them look "different" somehow, which would probably be a bad idea.
The MCU movies are an adaptation of the comics, not a literal representation. So Nick Fury being played by Samuel L. Jackson is a choice they're free to make, because they're not beholden to the comics to that extent. Fury's race was never one of the main focal points of his character, so making him non-white doesn't really make him any less true to the source material (and I believe that in the Marvel Ultimates, Fury's appearance was actually based on Sam Jackson). Characters like Storm, Shang-Chi, or Black Panther, for example, are different -- changing them to be of another ethnic background wouldn't make a lot of sense.
I guess what I'm trying to say is, the Thor movies don't claim to be historically accurate. They take place in an alternate reality where, for example, the Nazi organization Hydra still exists in modern day in spite of the Axis powers losing WWII. They
all require a lot of suspension of disbelief. Why couldn't Heimdall be black in that reality?
Bookmarks