When I look at the list from 2000 onwards, one thing that really stands out to me is that the majority of the interim coaches were either the DC or the ST coach taking over. And more often than not, it seemed like when it was an offensive guy taking over, it was someone with a heavy background as an OL coach. Obviously, not always...but that does seem to be the trend for the interim HCs in that timeframe.
So, in that sense, I think Thomas Brown is a bit different in that he is still young, has a bit of a varied background and I keep thinking back to him being an asst HC to McVay with the Rams. And he seems to have a strong personality that resonates with the players.
Time will tell, Brown has 5 games to show the front office how he leads. At the very least, he should deserve a real interview for the fulltime HC position.