De Boer is not a bad coach at all, the thing with de Boer he wanted to change too much at Palace like major changes to training, playing style etc it was far too much for the club to take even though they agreed this be done when de Boer got the job, they decided it was too much of a risk, so they went with a safe bet like Hodgson. De Boer is doing great in MLS again he has been allowed to do his own changes which did not go down well at first but now they are flourishing from it.
Regarding Ten Hag he is an exceptional coach, to just say anyone can win the league with Ajax is a total silly thing to say when Ajax never won the league for 5 years until last season. Ten Hag has brought in a style to how Ajax were back in the day with the total football education he has with his philosophies and his close working with Guardiola at Bayern Munich. I actually think he wouldnt want the Arsenal job in the fact he would want bigger as even Ajax now are at a higher level then this current Arsenal set up. Look what Ajax have done in the Champions League, winning in Madrid, Juventus, Tottenham etc Arsenal cant even beat Sheff Utd away let alone compete with any of those teams.
I are very skeptical to get an Italian coach, Arsenal's DNA is not the style of Italian football it is completely the opposite, then you might as well have Mourinho who is in that kind of mould.
Arsenal are a Europa Cup team with a Europa Cup Coach, that will not change for a while.