There are several things you can try to improve the situation: 1. Make sure you include a sulfate shampoo in your routine every 2-4 weeks to clean your scalp in depth and get rid of buildup. 2. Reduce the amount of oil in shampoo A and/or switch it for another oil like jojoba or grapeseed oil. 3. If it still is not working for you, you may want to try using a slightly stronger surfactant instead of coco-glucoside. You can try for example: Lauryl Glucoside or Sodium Cocoyl Isethionate. 4. Reducing oiliness is also about hydrating the scalp, you can try doing an aloe vera scalp mask 30min before your shampoo or between your shampoo and conditioner to sooth and hydrate the skin. 5. More about how to customize your shampoo and conditioner routine in the Hairqare Lab + product recommendations to find better products!