The FAQ seems contradictory on this point:

In the Wrecking Crew scenario, let’s say I draw a minion which has the “Guard” keyword . Does that Minion prevent me from attacking all of the villains, or only the active villain?

The guard keyword prevents you from attacking all the villains.

-Caleb

Then 3 questions later it says:

Can you use a card like Energy Daggers to attack every Wrecking Crew villain?

No. “Any card effect that refers to ‘the villain’ only refers to the active villain.”

– Wrecking Crew Rules Insert

These statements as written seem mutually exclusive as Guard is a card effect and does specifically state "the villain."

As this is a co-op game with little OP, I guess we can just rule it as we see it.

I just wish that the FAQ would have given clearer guidance going forward (a consistent standard that can be applied with common sense.)

I think I may simply ignore the first ruling in favor of the second as that lets me play everything as written. What do you guys think?

The RR for Guard says: While any minions with this keyword are engaged with a player, that player cannot attack villains without this keyword.

Italicized text on cards is a reminder, and doesn't override the rules. The base rule on Guard stops you from hitting any villains (plural). It doesn't refer to a singular villain, so the "only the active villain" doesn't apply.