The difference between Bateman and Welsby was a small fraction of a second. Both committed to put a big hit on a player, both used their arms to try and make a tackle, both made some sort of contact with the head, both went in with too much aggression and in the modern ruling of the game could have put the players safety at risk. The margins are tiny, i would say both were reckless tackles in todays language, Bateman was half a second later than Welsby and deserves a longer ban.
Knowles was a straightforward intentionally putting undue pressure on a joint and could easily cause ligament damage, he takes it way beyond an acceptable angle. I can't believe anyone tried to defend that with such clear evidence, and he wasn't given a straight red.
I agree that there are many other tackles with head contact that are not picked up on by commentary and just go unnoticed that are as bad as some of the above. The use of freeze frame has to be looked at and a threshold taken where the players reactions are taken into account for defender or attacker being unable to change the point of contact.
