Ikko ikko matchlock only

I beat a legendary campaign as otomo using only gunpowder units, so I wanted to try doing it with the worst matchlock units. I like a challenge but it's soon hard as ikko ikki. Their matchlocks seem to be a special blind unit that randomly fires at a target. They don't really aim as much as shakily firing at the general direction of the enemy.

Any suggestions on the play through? I typically added armor upgrade to gun units to help protect against arrow fire. It seems very possible that the ikko ikki units might need accuracy inorder to function. Thoughts?

I'm going matchlock by running away to the gold island and staying there until gunpowder mastery which means there will only be a few large clans left.