Mentors - What is expected really?

[Thamorian]

This is what it boils down to. Savage level content, including the Coils, is not in the Mentor roulette even two expansions after. That means Mentors aren't obligated to be know the game to such details, or even be such good players. Let's not fool ourselves into thinking the Mentor system is anything but a scheme to get queues moving.
And I mean, if someone made it into Savage and they don't have their rotation down, they don't need a Mentor, they need Jesus.

Mentor Roulettes came much later than the mentor system so no, it's not a scheme to get queues moving. And being able to do savage raiding and being a good mentor does not have much much in common. You can have a really really nasty and rude person be good at raiding and a mentor who is not good at raiding but can help teach new players about the game.