It's a good placeholder solution for a big problem, though it isn't a fix. Let's try and fix it. The problem here is that Tanks/Supports don't receive credit for killing bosses. This is a problem seeing that most (relevant) endgame content is boss killing. The credit for killing bosses is purely based off of damage. So, how about we add another credit for killing bosses? In guild wars, there's a score for how much damage a player has dealt. However, there's also scores for how much damage healed and damage taken. Simply implement that system into bosses (which will be difficult, I know), and Tanks and supports will be given tokens. Please let me know if I got something wrong or there was a misunderstanding.