I don't know about the rest of your stats, but the following Wade-coached teams had 500 or better records in December during his 9 years as HC.
1998 Bils
1999 Bills
2003 Falcons
2007 Cowboys (500 in Dec)
I also know it's inaccurate to penalize a coach for getting middling teams into wildcard playoff rounds where they are beat by better teams, which has happened to Wade at least two of the four playoff games he's had.
What you're doing is looking at strings of data that give you an incomplete picture, then drawing a wrong conclusion because that conclusion supports your insecurity about the current team. Wade doesn't get credit as a coach capable of getting his team deep into the playoffs because he hasn't done that yet, but you do need to at least try to look at his numbers in context to see if he's performed or not performed relative to expectations.