It's not BS if Moshiri has sacked managers who have finished mid table. More than once.
Moyes is not a glamarous enough name for Moshiri. Nowhere near the "Hollywood football" that was talked about when Moshiri arrived. Moshiri has always been swayed by a big-name appointment: Carlo an all-time great, Benitez with a CV of trophies, Koeman the playing legend etc etc. Then there's the rumours he wanted Diego Simeone, and even Pereira is known on the European stage.
I think it's very fair to say managerial appointments for stability's sake is not exactly Moshiri's primary thought.
Who have we sacked that finished mid table consistently though? Nothing to do with hollywood anythings - all of the managers you listed except Benitez (which was honestly bizarre) were seen as sensible, Carlo especially. Not even sure how you can say with all seriousness something negative about the Carlo appointment tbh.
Koeman up and coming and managed Barca after us.
Carlo Ancelotti is Carlo Ancelotti. If you can get him - you do.
Silva was/is an up and coming manager AT BEST when he got hired with us; a prospect if you will.
Boberto was sacked about 6 months too late.
Obese Samuel was signed and seen as a stop gap and this is what he was - grinding 0:0's along the way. He also managed 20-odd games, which makes the "stop gap" even more obvious.
Lampard is also an up-and-coming/"good for the future" type, with a project in mind, and now working with a DoF.