You can cut the point and flat apart easily, some people do that for comp cooking anyway. The problem is they are different, so your cooks will have different characteristics.
Are these competition cooks, or just for friends? Just for friends, I would cook it all at once, and reheat the leftovers.
For comps, you really ought to just get 2 briskets, but otherwise you have to cut the flat and point and cook either one. I doubt cutting it lengthwise to include both muscles would work well.
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