There are still one or two missions in the game where you need to stop <villain group> from destroying <maguffin> (A glowy, usually desk or crate).
On a large team, they're pretty much instafail, as there's a spawn round the glowy from the start and as soon as you get onto the same floor as said glowy, the spawn attacks it. Not always a problem solo at +0/x0. On a full team? Kaboom, loading screen, appear outside the mission door, you have failed the mission.
(And there's a special place in hell for the last fight in the last mission of Sutter. Primal Duray can feck right off (and regularly does, that's the problem)... )