The challenge, it seems, is that there's really no uniform thing as "1 oz of ginger". Weighing out ginger isn't like weighing out hop pellets and tossing them into the boil. The more surface area on your ginger, the more ginger flavor that's going to be extracted, and a little goes a long way.
This is a rough guess, but I'd try something like:
1oz of a whole, peeled chunk of ginger
.75oz of peeled and chopped ginger
.5oz of peeled and grated ginger
I think 2 cinnamon sticks is probably right. The more I ponder this, the more I don't think that my Xmas Ale is lacking cinnamon, per se; I think it's just getting overpowered by the ginger. The key to a good Xmas Ale is balance. I'm afraid that if you lower the ginger and boost up the cinnamon, you'll knock it out of balance in the other direction.