Stop asking my questions for me.
The concentration of men is getting deeper and deeper into the enemy's line, without going into the ditch completely. Once again, you're at a standstill. But now, at least, some of the pressure has been taken off of your men.
Calling a nearby lieutenant, you bark at him to gather 50 men, and attack the archers. Run around the battle if he has to, he must do it. With a stiff bow, he runs off, taking some of the uninjured men in the back line. This has the side effect of making the enemy think that some of your men are retreating. They howl and dash themselves at your men further. Fools.
You wait anxiously while your men fight and die, constantly wondering if your surprise attack worked or failed. Suddenly, you hear a scream. Several men, behind the line, sound like they're dying. The barbarians in the back of the enemy wave turn around, and are shocked to see a group of your soldiers butchering their almost defenseless archers. The bowmen have knives, some with swords, but none with any armor. They're as good as dead.
You expected the men to rush to the aid of their brethren. They don't, and continue fighting. Hmm...perhaps there is less loyalty in their ranks than you realize, or at least more common sense. Still, while this has not completely turned the tide of the battle in your favor, at least now you can do some real damage. And for all the enemy warriors' common sense, little do they realize that once your troops have either butchered the archers or driven them all away, they can easily charge the enemy's rear.
See, plans like this have a low chance of failing. Even if the enemy did make a good roll and rush to aid their bowmen, their line would have practically been broken.
I didn't actually roll the strike force's chance of getting there, they would get there, ultimately, and do damage. What I did roll was how the enemy would react.