I think you are correct, he'll still be here in 12 months, however the question might be in what role? Anyone who has been successful in emerging markets, like Mr Moshiri, is both a pragmatist and a realist. Clearly Martinez has many talents but he also has inherent weaknesses. It would not surprise me if Martinez becomes "head coach" with an additional coaching team alongside, specifically a defence coach,.
That would make no difference at all as long as Martinez is in charge of in game calls.
And at this point it's a fair enough assumption that he'll never be up to the job of managing us effectively mid-game on a consistent basis.
It all comes down to the end of the season. If we finish bottom half, I think he's definitely gone, but depending on just how abject we are, he could be gone with a 9th/10th place finish too. Moshiri won't want to come in and change managers, because he'll be afraid of being seen as interfering, but a few more results like that and fan pressure will make the choice easy for him.
One thing is for sure - anyone defending him at this point are doing so for very little reason, if any at all beyond just not wanting to admit Martinez isn't the manager they hoped for after Moyes.