Can I substitute the arrowroot and potato starch for cornstarch …

Name: Simple Sorghum Sourdough
Prep time: 30 min
Cook time: 1 h
Total time: PT-480261H11M20S
Cuisine: Gluten-Free
Ingredients: Day 1 1 cup sorghum flour (110g) (+ extra for dusting, optional)1 cup buckwheat flour (125g)1/2 cup sunflower or pumpkin seed flour (45g) (or a combo of both)* 1/2 cup arrowroot starch (60g)1/4 cup potato starch (not flour) (40g)3 tablespoons whole psyllium husk (20g)1 tablespoon coconut palm sugar (12g) (or maple syrup) 1-1/2 cups water, filtered or spring (room temp) (approx. 360g)1/4 cup olive oil (+ extra for topping, optional) Day 2 1 cup active (fed) sorghum sourdough starter (approx. 265g)1 tablespoon fermented beet juice, optional** 1/2 – 1 tablespoon sea salt (5-10g) Optional Seeds: sunflower, pumpkin, poppy, sesame, hemp