Also note that I haven't included the benefits of advantages gained from rolling even numbers, or the drawbacks of disadvantages gained from rolling odd numbers. I'm basically thinking that spending an advantage allows the player to boost a verb die by +d2 (I've included this in the procedure above). Spending two advantage points give an automatic success, or give everyone on your side a +d2 bonus for their next action (as long as this can be justified in the narrative). Spending three advantage points gives an automatic success to everyone on your side (again, as long as this can be justified). Disadvantage points might cancel out advantage points, or might be spent by the GM to inflict penalties (1 pt = -d2, 2pts = -d2 to everyone or -1 success, 3pts = -1 success to everyone).
I hope that this might encourage strategic thinking within the narrative. "I'll draw the fire in this direction (-1 success to me), which will give everyone else a better chance to accomplish their actions (+d2 to everyone else on my side)."