If we do have to lose one of Moises and Mac - and I think we probably do - I think I'd reluctantly choose Mac. Not so much on footballing grounds, but Mac is about three years older than Moises. Moises can better afford to give us one more season before moving on to his ten years at £5M+ a year...
I really rate Sanchez. Having said that, Steele has done fine and currently deserves to keep the place. Would still prefer Sanchez in the long term though.