unfortunately archers middle is just unexploitable. even cav cant reach them on the first round and infantry arriving in the second will take all the melee hits. its not the best line settings for every situation but it will never backfire. which i think exposes some very serious problems in the combat code.
There are few ways to deal with this. You only need to think about unit behaviors a bit and think outside of box.
Also, changing your army unit composition will help too. There are three ways to do this. Give incentives for people to switch over. Or you can ask people to change. Ask for volunteers for this though. Tell them your current problems and suggest to people as a whole that you need more of this or that. Lastly, you can just get rid RCs you don't want your nobles to hire. Extreme but efficient. Will cost a lot though.
