[Mithalwen]

I don't see that there is a huge problem. I can't recall him using canon as a term but I might be wrong. In note39 to Cirion and Eorl in UT he suggests independent and distinct traditions to re solve differences in versions of the origins of the house of Dol Amroth which doesn't suggest a slave to the concept of canon.

I find that there are almost always factual errors anytime anything I happen to really know about is reported in the media and there are often variants in legends, even in the interpretation of historical evidence, it is almost more authentic to have variants in a synthetic mythology. As with real history it is a question of balancing evidence and probabilities. Of course not everyone is going to get involved in it the texts to that extent.