Statistically meaningless comparisons.
2020 Steelers? Since 2016, Tomlin has turned into the worst playoff coach in the NFL. They are 0-5 the past 9 seasons, with one and dones in 2020, 2021, 2023, 2024. The 2020 season isn't a meaningful data point for your purposes.
2006 Colts? They had one and done postseasons not just in 2007--under Dungy, despite HOF talent all over the field, exited without a win in 2002, 2005, 2008 as well. No HC in history squandered a more talented roster in the postseason