Combat system is beyond saving.

[xivYuiM]

I can't quite remember- I wonder if I missed the time when this was the case in regards to Tanking

When was it that Tanks had to make macros to mark the kill order of dungeon trash so the DPS wouldn't attack an enemy the Tank wasn't attacking and pull aggro from them?

Yes tanks marking kill order was common for dungeon packs especially for the first couple of enemies or if you had a DPS with strong single target weaves because managing aggro was always an engaging minigame and people who try to dismiss it are wrong.