I was at the game on Friday. Hawks did a "blocking"/intercept marking drill for quite a while in the warm-up. Like so many things in this game, it's a question of how far you can push it, and what is then interpreted as an infringement.
The HTBs/tackles are terrible and they should just pay them immediately, get rid of prior opportunity.
I don't mind prior opportunity but once gone, the player with the ball must dispose of it legitimately i.e. by hand or foot. So many balls were "knocked out in the tackle" on Friday night. Eliminate this one interpretation and it will get rid of so much congestion and render the Swans and Cats less effective, a win-win.
The low risk vs high reward is getting exploited by the Dangerfields and Selwoods and Sydneys of this game. Grab ball, try to bust out of a pack, chances of getting or contributing to high tackle = high, chances of getting caught HTB = low. High chance of retaining or transferring possession, medium chance of a 50/50 ball, very low chance of a turnover.