Often times forcing every member of the PC's to make a check almost guarantees failure for the group. If everyone needs to sneak through a base or lie to get past a bouncer, there is often at least one person who is going to be weak with the applicable skill. But the best can be a guide, or speak for everyone. How would/do you handle this mechanically. Allow the best to make the roll, but add setback for each person they are helping? Or maybe upgrade for each person they are helping? Have them do a leadership check to distribute boost dice?
There is probably a specific rule for this that I am just unaware of.