{cross} = "Kill Next" or "Kill Last" ?

This seems to shift around depending what servers I happen to have in my pugs, and I only really find that anyone bothers using raid symbols in 5m trial jousting and for the first boss, but what kill order is the red X?

It seems universally understood that {skull} will always die first, but after that I find my pugs tend to fall into absolute chaos as far as the next marked target to attack. I personally always saw {cross} as a literal "No" or "Wrong" symbol and assumed it would be killed last and whatever random symbol that would otherwise be used was the "Kill 2nd" target, but I usually see everyone cluster the X as soon as the Skull dies.

What kill order is {cross} for you?