I definitely agree that he is a player for a 3 man midfield. For a 2 man midfield normally you need less specialist, more complete players.
it's working like a charm

as for arthur, he's very good at holding the ball, plus as you pointed out, his passing accuracy is outstanding. but he offers little otherwise - that's why we need to put 2 other mids near him: to do the dirty job of running and taking on opposition, plus make the forward runs and passes. (bentancur's passing accuracy is inheritedly worse as he makes a lot more forward passes, which are way more riskier than arthur's low risk, short passing holding game.)
