Give them an Evasion ability with 20% chance to miss.
You're expecting a help but turn down very negatively towards helper that tried to help you, good luck.
Also, you expect people to give detailed solution while you just gave them very few perspective of your problem.
You explain in a simple way, people also explain in a simple way, it's common sense.
lol. So he wants the archers to have a 20% chance for himself or even for his foes that he is attacking. Its beyond simple. Yet he is do defensive about suggestions.