well, I mean, things the player has to do at that level, like construct ships, run freighters around, assemble & move fleets around, etc, should be in, though simulating things like internal politics and coffee breaks would be unnecessary.
Basically, if it has a major impact on gameplay and makes sense to have (or the simpler alternatives simply don't cut it), then it should probably be in (ie, in Transcendence, there are a lot of simultaneous wars being waged, but yet no fleet movements are seen, no systems are captured, etc, resulting in some rather jarring plot-gameplay segregation. For the main game, this can work, because you only see a fraction of the systems in the quarantine zone, but in TSB you can visit all of them, so simulating the wars becomes much more necessary. It also means that tie-in missions can be added, and by fully simulating strategic level decisions, it provides a much more sensible and realistic sense of scope: ie, a back-water system of no strategic importance at a dead-end stargate node is unlikely to have anyone vying for it, while a hub system or one with valuable resources will be heavily sought after. Since the gate topology and system contents are procedurally generated, it can't be pre-scripted.)
