Your explanation of me being incorrect is with examples of S6 (all star game)who drifted apart (and became their own problem) and Kail's alliance that has her without the support of her alliance members. (and will end up like S6).
Sure.. if the alliance is weak and it breaks up ... sure... they'll maybe lose the game... who knows?
My explanation comes from "Chill Town". An alliance of 4 that didn't break up. (Dr. Wil, Boogie, Jenna, and Erica)
What your failing to realize is the floaters. A Fad 4 isn't just a Fad 4. You need to factor in the rest of the equation. Chill Town won because the Fad 4 had floaters... as all alliances will have. If you have 4 people in a group it is very unlikely that no floaters will exist.
Chill Town Alliance (Wil, Boogie, Jenna, and Erica) had floaters. Erica had Danielle (a close friend who she could sway here and there). Jenna had Kayzar, Wil had James, and Boogie had people like Chicken George like everyone else in the house lol.
The floaters ... which will always exist and be available to the Fad 4 for their destruction turns the Fad 4 into an uncontrollable Fad 5, or 6, or 7.... keeping in mind their own promise to each other to be the last 4 standing.