Since the blog had a request I'll continue the thought on how a Team Based Rogues Gallery works. (After all, I did indicate that there would be a card for it).
Obviously the team's rogues gallery needs to have members who are potent enough to challenge the whole team. It is also highly unlikely to have a single theme, especially if it is an Avengers or JLA style game where some of the team members have their own books and rogues galleries and some don't. The standard elements of a team Rogues gallery are:
Rogues United: this is a villain team made up of members of the A-List or Own Book Heroes rogues galleries. The Masters of Evil, the Injustice Gang, and other similar organizations are good examples of this. Each Villain is as powerful as their counterparts, but sometimes there are fewer of them then there are team mambers and sometimes they wildly outnumber the heroes, depending on the story. They generally act to destroy the hero team out of enmity with their primary foe.
Schemer and recruits: this is another villain team made up of a single smart/clever/plan oriented villain and the people he's hired/made/conned into attacking the heroes. This is superficially similar to a Rogues United situation but other than the schemer the villains may have no connection with the heroes at all prior to their first encounter. The Frightful Four is the best example of this - the Wizard and Paste Pot Pete were Human Torch villains but Sandman and their rotating cast of 4th members? No reason for them to be there. This means the Schemer is likely to have a couple of rotating slots to keep the encounters fresh.
Only you stand to stop me: this is the villain somehow convinced that if the heroes were out of the way (and just this one band of heroes) the world/country/city would fall before his might. Now, depending on the hero group this might well be true, but it means the villain's motivation is pretty clear. Now, they might be obsessed with winning in a straight up fight, or turning the heroes to their side, but the upshot is a single powerful villain (likely backed up with hordes of henchmen) need to defeat the team.
I WILL CRUSH YOU: Very similar to the last one, this is predicated on a particular hate for the team by the villain, who is again likely pretty tough and has an army of minions (or in this case perhaps deathtraps).
B-Lister Villains Unite!: Each of the heroes who only appear in the book have a single personal enemy - likely good for arriving to harass them and through extension the team - who holds the aspects of a rogues gallery of they had one. However sometimes those B-Listers join forces in a team that really only ties back to the Team book. This makes the conflict more personal than a Rogues United. And there's nothing that says these villains have to be weak, so the threat they pose can be real - the A- and B- List division is only about who has their own books - Captain America Villains are not more powerful than Wonder Man foes just because Cap has his own long running book.
That's what I have immediately. More may come to me, but if the team has a real theme (the FF are all explorers) then use the themed rogues galleries from an individual hero. The types of villain that teams face as a whole are pretty static. This is why its important to have the individual rogues galleries to draw from