How do I best fight missile heavy factions?

[Sloty]

Like Hungary for example.
They have lots of archers, skirmishers and missile cavalry.
How can I increase my chances to win against them?

[lolIsuck]

Have more missiles is the simplest answer, preferably long range missile units but as most horse archers tend to get really close to your lines any archer unit will do. Once the missile cav is gone the foot archers can just be run over with cavalry. It's a waste of cavalry to do this whilst they still have a lot of horse archers though. so they have to be defeated first.
I don't know which faction you're playing but mourtatoi are a great unit to counter the enemy's missiles, put them behind some spear units and fire ahead. The enemy will focus on your spearmen while you steadily destroy their missiles.