How hard is it to macro a marking icon to your pulling ability like tomahawk? Not very hard. The least you could do is make that macro so that people know which target you are focused on. If you're a good tank, that's a good practice, then you should be rotating your enmity abilities through the rest of the pull to keep it going on you. Then you should be focusing on the target DPS is attacking next, which is usually the mob with the next lowest health pool, which you can control by attacking your desired 2nd target after you've secured significant enmity on your primary target.

You spent 100x more time making a post about anti-marking when you could have made that macro and solved the problem. It's not like people in your DF groups are going to come here and read your post and have a new view of the issue at hand. You're the "leader" of the group. I think tanks should act like it.