I took the previous reviewers advice regarding there being too much sage so used less than half the amount and counted the medium and large leaves as two. This is still too much sage. I ended up picking out at least half of the sage at the end.
I waited until the end to use the garlic, putting the garlic in the butter before the sage to add more flavor.
I overcooked the turnips and sweet potatoes and they kept in more of the water when I drained them, my mistake. After they were done I cooked them on low for 10 minutes and this gave them a fluffier texture.
Would definitely make again, using just 1/4 the amount of sage and watching closely to avoid overcooking.