Giannis is approaching age 30, and the rest of the Bucks' (very) aging roster isn't getting any younger.
We've got one glorious championship in the bag, but in order to really have the type of impact we would all like to see, and none moreso than Giannis, can we afford to spend several years of his prime with an untested coach who might not be cut out for the job, watching them flounder and waste away the best years of his prime?
We all know the risks of a first time head coach: the job could be too big, the spotlight too bright, they might not be cut out to manage things from the top, they might get overwhelmed, their schemes might be too elementary when they're the ones leading the charge, they might not understand timeout usage and challenge usage and substitution patterns, and worst of all, they might just not be nearly as good as their strong background and sharp interview skills might suggest.
If we bring in an untested head coach and they fail to move the needle, by the time we're able to move on, Khris, Jrue, and Brook would likely be too old to be major players for a championship contender, and too old to matter much as trade chips either. That might be it for the Bucks run of championship-contender rosters, at least for another few seasons as we reload around a Giannis who would then be mid-30's (with a game that many including me worry will age poorly).
So can we afford to hire an unproven, first time head coach?
I would argue that we can't afford NOT TO.
All of what I said in regards to the dangers are true, every word and worry. So what would be the solution? Hire a coach who has proven to be unable to get teams over the hump? Who has had a chance, and proven to not quite be up to the task, to be solid, or mediocre, and hope that they have improved since then? Cross our fingers and hope that anybody except Bud can win multiple championships with Giannis as long as they're at least competent? No. I can't think of a more surefire way to waste Giannis's prime, and their roster, than that.
The Bucks need innovative leadership, transformational change, and a unique vision. That is what is going to turn this flagging, aging, asset-baren, boring roster back into a competitive championship group, hungry for another title. I don't believe that is going to come from a Monty Williams, a Scott Brooks, and certainly not a Mark Jackson.
Instead, though the risk is present, and perhaps high, I believe it will come from a current unproven coach, who is hungry to prove themselves, and who has spent years honing their mind, learning the league, and planning for their moment. Someone who can reflect the tenacity and passion of Giannis, the adaptability of Brook, the reliability of Khris, and the professionalism of Jrue, but also someone who is ahead of all of them in basketball acumen and strategy. I don't know who that candidate is (though I have some ideas), but I'm pretty sure I know who it isn't.