The math on exploding sixes is tricky. Basically, short of having 18 dice to roll, exploding sixes aren't likely to get you much (one 6 rolled per 6 dice, 1/3 of which will result in an additional hit). Rerolling failures is usually the better bet. In short, an average exploding sixes will get you one extra hit per 18 dice (adding your Edge to the roll is useful if you have a high edge at one extra hit per 3 Edge).
So, in this case with your 4 Edge, you are looking at, rounding to nearest, 2 extra hits (one from the Edge dice, one from exploding sixes). Rerolling on 9 dice is also two extra hits (from the average 6 misses on 9 dice), so it's largely a wash.
I didn't realize that your Intimidate was so low, only allowing you to use one hit from teamwork. We might have had better luck with one of the other Intimidators. Both Sam and Kat have the same dice pool, but can use more dice from a teamwork test due to their higher Intimidate skill. Oddly, we have no idea what Chino's Cha and Intimidate are. But, nothing will save you from a poor roll - ask Ohanzee.