Shaw is a far better player, any new player bias aside. My hope is that some genuine fear of losing his place might kick Shaw up the ass and get him back on form - as having the best version of Shaw in this current team would be far more beneficial to us than what we are currently getting with Malacia I reckon. Shaw has the ability to carry the ball up the field, excellent passing and crossing too, which would benefit Sancho a lot.
Again, I expect a lot of improvement from Malacia once he settles, but his performances have been over-praised to me.