A scanlation group actually working together would probably blow me out of the water. It's just that with me, I'm either busy with work or free to work on a manga if I want and get actual progress. In a group, though, everyone has a specific role, so it's like this incredibly delicate machine with a buncha cogs and gears. If even one of those gears breaks (like, say, typesetter gets hit by a car, QC has midterms, translator is getting married, etc) then the whole thing grinds to a complete halt. And when you fix one, another one breaks down.