Yes they have made mistakes but lets face it who dosnt.
I'm not looking to bag the ownership too much (you are right; they deserve praise) but it seems like they don't always learn from their mistakes.
The football administration of the club has been weak for years. If they want to go with rookie coaches then having a Director of Football role that leads recruitment, playing style and vision leading is a solid option. Most clubs in the A-League have those or equivalent roles. The ones who don't e.g. Newcastle have very experienced football management with Ernie and Lawrie McKinna.
The Welnix should have recruited a DoF after Ernie left. I think, even now with the license uncertainty, they should still look to have this role (if they can find someone).
If it goes tits up with Talay, which it very well could, then you have someone able to still guide the football side of things over the long term. If growing Greenie in to a first team coach is what the club want to do then the DoF can guide the clubs footballing resources to that end as well.
Recruitment and retention is also largely moved away from the head coach and the head coach primarily concentrates on getting the best out of the players and on-field results.
I'm not sure the reticence of Welnix to use a DoF or, again, whether Wellington can attract the right people (being a footballing outpost).