I don’t think it’s impossible, but I would assume that either the runner is underachieving in the 200m or that he is a 400/800 runner. I know of a 45sec 400m guy who has never broken 21. Coincedently he’s since changed his focus from the 200/400 to the 800m;)
I don’t think that any sprinter type 400m runner(200/400) will get into the 46 range until they have the basic speed. And that speed seems to start in the 21.low range. I’m talking 21.3 and below. Most of the sub47.00 athletes that i’ve noticed who haven’t run that fast are giving the majority of their attention to the 400m.