Agreed Chris. Listen, all managers have their "sell by" date and it doesn't matter whether they fall on their own sword or if the club decide they've had enough, soon or later the reaper cometh.
There are very few managers who stay longer than 5 years with a club and those who do are generally with teams that are really settled in relatively safe places. Dario Grady at Crewe was an exception and it didn't really matter whether they were promoted of relegated, they stuck with him for over 20 years. (I think he was even managing director at one time as well). He was probably able to work within a tight budget and I cannot believe he was on stellar wages either.
Two other managers who were exceptions were Sir Alex and Arsene Wenger. Somehow how other they managed to keep a tight rein on their clubs and I can only think that was because the players truly respected them, and what they had achieved. Both were multiple league champions, home cup winners and European cup winners however ultimately even their results started going against them leading to a parting of the ways. If I were being cynical I could also say that neither their clubs has achieved anything like the same results but maybe they themselves were lucky in inheriting a golden group of players like those of 92 at ManUre. Thinking about it, Wenger was probably the more astute of the pair as he bought most of his team, and didn't he do well!
Regarding SE I think he will disappear of the horizon soon enough - his track record shows that he is not a "stayer" however midtable mediocrity under him is preferable over someone like JED, (who when came in (allegedly) was given a budget way in excess of what his predecessors had received - blew the lot and was sacked in less than 2 years.
There are times I really have some sympathy for Paul Scally - I truly believe he wants to do right by us but with finances fairly limited he is really having to cast his net in the darker waters of the pond. Not too many gems have come out there. Mike Flynn being an exception - I had hoped that he might come to us given his time here but that looks like a non-starter.