Crossbow or throwing weapons for peasant militia?

I used to have this thing where I had all of my men have a thrown weapon and use them within the first two or three rounds of the battle.

But is time went on and they became ineffective, I stopped using them and just gave them polearms and other stuff.

If you want your brothers to attack a foe when they're blocked by things like trees or other brothers, or as a secondary weapon, what should they use?