Help/interfere: Before or after?

I've been wondering, and can't seem to get a grasp on the rules on this.

Do you roll for helping/interfering before or after the roll that you want to influence?

So far, the one group I've been playing AW with have gone with after, mainly because ...I'm not sure, we just called it like that and now it's all established. But what do I tell the MC of my new AW group when this comes up? It's a pretty damn crucial difference, and I'm supposed to be the one who knows this stuff.

I don't have a lot of table experience with AW, but I hope this helps!

AW p205-206 says:

It's best if both the players -- the acting one, the helping or interfering one -- roll at the same time, but don't be a nit about it. If the player's like "oh wait a second! I provide covering fire of course, am I too late to roll to help?" the answer's no, not too late.

So, RAW, it should be simultaneous, but it's okay if it's immediately after. I'm sure the "To do it, do it" rule would also address some of the fictional issues -- you should probably already agree on who's going along with you before you roll, so you know who's helping.

Does that cover your question?

Yep, that covers it, thanks!