Sure, it’s a bigger sample in raw numbers. And absolutely, club / roster strength is a big factor.
But BA has a considerable edge in terms of percentage of seasons in which he’s taken his teams to finals (5/9 for BA for 55%, vs 8/19 for Ricky for 42%), yet Ricky has a 62.5% finals win rate (15:9), vs BA’s 33% (4:8).
The only sample size that is (barely) statistically significant is Stuart's 20+ career finals games. His 13 games at Canberra+Cronulla is a small sample and Arthur's 12 games is even smaller. Remember Stuart had an 80% record after his first ten finals matches. It is statistically insignificant.
Arthur has made the finals five times in nine seasons, which is slightly better than in the preceding nine seasons, so maybe it's more to do with the club than the coach? The nine years before that we made the finals six times, and in the nine before that we never made the finals. So with 15 finals appearances in the past 36 years we can see that Brad Arthur is well ahead of our long/medium term average. We have sucked (overall) for 36 years, interspersed with brief periods of adequacy. Has sacking coaches ever fixed anything? The only thing giving me hope is this:
Arthur's nine years can be broken into two distinct periods, pre-reform and post-reform. He made the finals once in five years prior to the 2019 reform, and then every year since.
Almost as though none of these stats mean much of a shit, other than neither has proven any aptitude to win a premiership post-2002. That is, of course, in the context of both of them being at their respective current clubs since 2014 inclusive. So if they haven’t done it in that timeframe, what would lead one to think either is likely to jag one, given they’ve each had relevant input into their rosters for the better part of a decade?
Well I don't actually think Bellamy or Bennett would reliably win a premiership in a decade at either club. You don't get to build your squad forever until you win a comp, the salary cap makes sure of that.
None of this is to defend Ricky, I think he’s pretty much toxic as a coach and he lost the bulk of his dressing room in mid-2021 (coincidentally, it was the game where we belted them in Canberra that broke the camel’s back). But I think this really just goes to show that both of them are well past their used-by dates in their current clubs.
I don't think coaches have use by dates if they are at a club where expectations match the resourcing, but I'm sure Arthur will be gone eventually. Whichever coach we get, hopefully he gets even more resourcing than we have now, which I suspect is already better than most coaches. But I'm sure it's a lot less than a few get to play with, much like Rick Stuart in his first few years of coaching.