Valverde had 2.5 season to change things, Setien will definitely be given one full season to show what he can do unless something disastrous will happen like losing to RM 5-0 plus trophyless season.
Yes, but we were all disheartened Valverde got so much time, when it was obvious after a while that he doesn't have what it takes. Also, now the conditions are worse than during Valverde, simply because the great players who won us these leagues are 3 years older, approaching their retirement. So to still allow them to run things it's near suicidal for the team. So now we need a top manager even more than in the summer of 2017. There is a difference between a 29-30 years old Messi and Suarez, and the 33 years old versions. Patch-work doesn't work anymore. We're approaching a period where we simply have to move on the pampered veterans or turn into a washed up club.
Time is running out. It's a possibility that if we don't change things and the rivals get stronger, we'll have some barren years with no La Liga titles. Then everyone, including the board will start to panic. I would like to see things moving in the right direction faster, starting now. You don't have to wait until you are in full blown crisis to react. You need to react faster to prevent that.
We should have reacted post Lucho, that was the right time, but we brought in a yes man who has kept the status quo and developed no-one. So we are in a situation where we have to start rebuilding now, even at the cost of winning no titles for 1-2 seasons. But first you need the right manager, and this is what we need to find out about Setien for the next 6 - 18 months.
Things are currently leading to Font + Xavi in 2021. Unless Setien proves he is the right guy for the job in the next period.