I looked at some other clubs, clubs that are usually appreciated by football fans with the way they operate. Here are the number of full-time managers they've each had in the last 20 years:
Dortmund: 11
Barcelona:10
Inter: 13
Each of these clubs had a fair share of "trigger happy" sackings of their own. None of Gasperini, Ranieri, Benitez, De Boer, Bosz, Koeman and Rose enjoyed much time or patience from their respective boards . None of them even made it to the aforementioned 18 month threshold. In fact, most didn't even get a full season. Inter sacked Gasperini after 5 matches, De Boer after 14 matches, and Ranieri after 35 matches. Dortmund sacked Bosz after 24 matches. The list goes on.
The picture is clear to me. We're not trigger happy at all, whatever that means. These clubs would have never tolerated what we have been tolerating since last November. Even though I still prefer him to an interim, if Ange indeed gets the sack soon, it won't be because Levy/board made a rash decision. Far from it.