Will Smith even be able to bat tomorrow? He's going to be sore as hell.
Batsmen are hit on the head an awful lot nowadays. Symptom of the increased protection - makes them less cautious, reduces their self-preservation instincts, causes them to play more shots and watch the ball less carefully. Smith played both the balls that hit him very badly. The one that got him on the arm was fast and straight, but not that short tbh, not much above stump height. The one that got him on the neck, as someone said, he ended up ducking into it. Again, it was fast and straight, but it lifted from not that short a length, which may be what got him. Bouncers are always a little slower than full-pitched deliveries as the ball slows when it bounces, and it bounces earlier in its route, so to get one to 93 mph is a phenomenal effort.
As to the fairness of Archer's bowling, absolutely 100% fair. His lengths were no different from the ones Cummins bowled first innings. If anything they were fuller. He's just faster and better at it than Cummins. Just too good. Maybe one or two batsmen need to rethink their scoring options when they face genuine quicks. Maybe the pull and hook are not clever options. The duck and sway might be wiser. And keeping your eye on it as well - Smith didn't do that. Not saying that's easy, but it's what the great players of fast bowling do. Archer uncovered a weakness in Smith's batting today, a weakness that perhaps exposes his shuffling technique somewhat, a weakness that perhaps only he and Mark Wood will be physically able to exploit.
And yes, maybe when Archer next comes out to bat, they might want to think about pitching it up.