Mmm, I really don't know anything about the early war... Did Starscream take over Vos in canon, and if so, which one? I know fanon tends to combine canon backstories and use the same set of logical extrapolations - speaking of which, when Starscream starts giving his expositional backstory for Skyfire, Megatron says something like "that must have been just before our final falling-out with the Autobots." Ever since I noticed that, I've been boggling at the implications. First, that the war was brewing when Skyfire crashed; second, that Autobots and Decepticons were pre-existing factions that split; third, that long-distance exploratory missions like theirs were only happening just before the war - and from that we can probably determine that they were sent to find energon, and yeah, things were probably not fantastic when Starscream got back. But if they left just before the split, who's to say the war hadn't already started when Starscream returned? They might have been caught up in it whether or not Skyfire crashed. Or even come back later, with energon. So many possibilities!