With a Sword, you can hit only one opponent at a time, but it will take a lot of damage, making short work of the big tough baddies standing in your way.
A Lance will hit up to three opponents, but with limited damage to each. Great for cleaning up groups, as long as they are not too big..
Bows will also hit up to three, and can even hit opponents which are blocked by others. However, the price for this flexibility is even less damage.
It is up to you to choose the best combination!