And by the way, here I don't understand why the archers should retreat. According to the rules, the attacker must win the battle or retreat. Skeletons attacked. Let them win.
If the archers do not put themselves in a position to be attacked, in my opinion, this is something similar to deliberately wasting time and not making a move in battle (let the opponent win however they want, when they simply don't get a turn). Or, in a losing game, not surrendering, but simply doing nothing and waiting for the entire timer to run out each turn. There is nothing in the rules against such things, but it is unlikely to be considered adequate behavior. I don't know if it is possible to adequately describe such situations in the rules.