Morrissey has always used hyperbole to make a point when he's praising someone, especially his collaborators. Have a look at this from '85:
http://foreverill.com/interviews/1985/dreamer.htm
"When I first heard Johnny play, that was in a sense almost irrelevant. The awakening had occurred days earlier with the meeting. I'd reached a stage back then where I was so utterly impressed and infatuated that even if he couldn't have played it didn't matter somehow because the seeds were there and from those seeds anything could sprout. Johnny had grasped the thread of all that was relevant and yet he was - and remains - a very happy-go-lucky, optimistic person who was interested in doing it now. Not tomorrow, but right now!
Now this was truly extraordinary because in a musical sense I'd only just met people who were total sluts, who'd rather sit around at home night after night talking about picking the guitar up instead of just grabbing it and saying 'What about this?'. Also he appeared at a time when I was deeper than the depths, if you like. And he provided me with this massive energy boost. I could feel Johnny's energy just seething inside of me."
This from a TTY Q&A in 2005:
"Whatever I said about the Smiths' abilities I meant. I very genuinely thought the music was Art, and I felt awed by it, and all of the groups of the day I saw as not-art. I thought Johnny was the greatest .... and also .... those masterful bass-lines ..."
& finally, he said this about Alain in the liner notes for the Southpaw Grammar reissue:
"Alain, for me, provides the best of moments : the climbing-falling solo of “Reader Meet Author” and the impish shadow backing vocals of “BFOTP”. Alain was best when he least tried and when he was certain that no-one was looking. You can tell a lot about a person from the sound of their voice, as you can tell everything about a person from the way they sing. There is enough of the cattle-prod of pain in Alain's voice to make the heart think, but will he see out his Morrissey days without a single line of press recognition?"
If he genuinely, 100% believes that his current set of hacks are better than Marr and better than Alain, then not only does he need his head looking at(!), but he's directly contradicting past statements about the quality of his band and his former collaborators.
Unless of course...Morrissey thinks this band are the "best" for a reason unrelated to their actual musical abilities, which is perfectly possible - if a little nonsensical in the context of his career aims.