I think he'll actually do well for Liverpool. Probably task him with what Wijnaldum was asked primarily to do under him and that's recycle the ball.
I don't think there will be any miracle. This is just a back up for Liverpool's crisis time. Arthur is an anti Klopp's player. Too fat that injury himself, low stamina can't play in one half and can't pass the ball forward.
But wijnaldum was tracking a lot and pressuring constantly. Arthur in no way bringin that to table