most GF pugs cant even get past the fabricator in KP
I haven't yet been in a pug that couldn't eventually kill the fabricator. The rooms with the hunter-creeper droids are much worse; on average, there's two or three wipes or near-wipes in those.
On the other hand, there's one mechanic in the Soa fight in EV I'm a bit surprised no one has mentioned yet. Half the time I'm doing that operation through GF, the group is unable to descend the platforms properly. For a variety of reasons people don't get healed, and by the time we reach the bottom half the group is dead. This is especially annoying because the operation can take two hours with a pug, and at the end I don't even get the reward as people give up after the third wipe at Soa.