I think that's a very fine idea indeed Revelations. I have oft told people that a whole game of 40k is only supposed to represent one turn of Epic, because there's loads 'off the table' that you don't see, and the scale is supposed to show a critical moment in a bigger (wider, longer) battle.
I also like the idea of using different force elements for specific objectives. I refer the honourable gentleman to a similar idea I put forward 18 months or so ago, back in 4th Ed when I was trying out various Combat Patrol combos here
So no, it doesn't have to be linear. I was thinking linear, because I was taking the Macragge booklet as a model, but even that has a certain amount of 'simultaneous action'.
:happy to be in several places at once cyclops: