Perhaps, for parallelism with the second half, and to capture the surprise twist of allegiance which I imagine DoubleAught wanted in the first chapter, it could have gone something like this:
After M2, we try a variant where instead of Blake freeing us from Pfhor captivity, Tycho frees us, to gain his own freedom from the Pfhor, and under him we fight against Blake and his men as they search for Thoth. (Parallel to "Envy" where Tycho frees us from the Pfhor, but we defect from the mission against Blake and his men to go find Thoth ourselves). When things go cross-eyed anyway, we try the opposite approach, and going back further in time, when Durandal's ship is under attack by Battle Group Seven, instead of helping defend him, we stay behind and held defend Blake and his men, leaving Durandal to the bugs (parallel to "Rage" part 2, where we join the Pfhor forces assaulting Durandal's ship). When that goes cross-eyed anyway, we go back to before the beginning of M2 ("Rage" part 1), except that ends up just segueing into the events of M2 we already know are doomed...
So we switch to the Tycho wing, where we were captured by the Pfhor at Marathon along with Tycho and now he is using us to free himself. That ends up with Durandal, Blake and the Bobs recapitulating the events of M2 anyway ("Despair"), so we try a variant where we actively join the attack on Durandal's ship when Battle Group Seven arrives ("Rage" part 2), which is still a wreck so we find a timeline where Tycho frees us from our Pfhor prison before the Bobs can activate Thoth, and from there defect from our assigned mission against the Bobs to find Thoth ourselves and merge Durandal's pattern into him, securing victory at last.
