Can I substitute pumpkin for the squash in this recipe?

I am making Three Sisters Stew for Samhain and I don't have any ernut squash. Can I substitute pumpkin for it? Should I not add the garlic if I do? I am having cornbread muffins and homemade buns with it. Dessert is candy bar Cheesecake with fudge sauce. Plus I also have various cookies, quick breads and old fashioned carmel apples too.