Mata is also a good few years older, I think he’s 34 or 35 now. I always felt he was a little too slow for a number 10, and certainly the wing slot we crowbarred him into, but that in an adventurous 4-3-3 he could have been an excellent player in the vein of his former Valencia teammate David Silva.
Erikson likely won’t play every week, it will depend upon opponent, but he’s someone who should be equally comfortable in 8 or 10 and can do a job wide in a narrower formation. Also it will be nice to have a dangerous set piece option for once too!