I think I left out some key details when describing the original plan earlier.

If we want to go with the most realistic scenario and please everybody, I ought to rectify that:
The idea was that Red Claw needs more time for all of the fast biters to get into attack position, so he sends Thud and Screech to stall the leafeaters. When they are given the offer to negotiate, the pair (along with Red Claw, who could probably hear it from a distance) decides that this would be a good way to buy time, so they accept. When the insult is accidentally translated, one or more of the three sharpteeth attack. Earlier, when I was playing Red Claw, I had him mention that he had told the fast biters to strike when he, Screech, and Thud did; the attack in itself is the signal. So whether the character is so angered by the insult that he lunges without thinking, or decides that the fast biters must be ready by then anyway, his attack is what causes the battle to begin.
A couple of my personal opinions: First, I think it would make sense if Chronicler's group came forward to meet with Screech and Thud, with both Red Claw and the herd remaining at a distance. It would allow them to meet on relatively equal terms, without a posse of leafeaters or a huge sharptooth threatening either side. Keep in mind that Screech is burdened by Pangaea, and Chronicler has a bamboo pole and Claw on his side, so the two groups would be pretty evenly matched in a fight.
Second, I prefer the idea of a single accidentally translated insult starting the fight. (Can Claw speak/understand Sharptooth? I was under the impression that he couldn’t, and if that's the case, then Chomper would need to mistakenly translate two insults, which seems excessively incompetent to me.) Obviously, if the insult that starts the fight relates to Red Claw's blindness, then he would be the one who reacts to it. It could be that Claw mentions Red Claw's blindness, it is translated by Chomper (if I am correct that he cannot speak Sharptooth), and Red Claw hears it from afar and charges towards the group in anger. Personally, I think that may be the best way to go.
What do the rest of you think?