I subscribed to a similar view on Martinez. That being said, his Xg was 25 and total was 17. We made lots of chanced for Lukaku and he didn't finish them. The reality is, his finishing helped cover up the cracks for Koeman. Martinez gambled on Barkley, Lukaku and Deulofeu coming good, which unfortunately they didn't. I probably think now what did for him was his strengths not holding up, as opposed to his weaknesses. Lets have it this way, if Lukaku had scored 30+ goals most of the extra in the first half of the season we go into Christmas in the top 4. I still think we have a dip, but from a much higher point and arguably a far shallower drop.
I still think Martinez probably goes a similar way but slower, his vision was utopian and not ideal for England. But then thats what people have been cuing up to say of Pep and he seems to be re-writing that a little bit.
As for Koeman yes I agree. I think Moyes, particularly at the end became a bit up himself though I do think he cared about the club, and Martinez would do as well. I don't mind Koeman's arrogance, but you had better make sure you produce results if thats your attitude.
I like long term appointments. Thats what is keeping my support for Koeman. However you do have to say, he has never shown any interest in being here longer than 18 more months. So what can he realistically build in that time?