I'm leaning towards the Tomahawk having a design flaw or really poor quality control, as mentioned in several other threads and related to a good MANY other threads, because we've seen way too many instances of people replacing a Tomahawk B450 board that was having issues with something else and no more problems. Sorry, but the Tomahawk and Mortar boards are fully off my recommended list regardlesss that some people don't have any apparent issues with them because a lot of other people, do.
I'd take the Steel legend over that board any day of the week. However, the X470 Prime you listed in the original post, would be the board I'd choose out of the three you listed. It's just a better overall quality board than these others.