In Chapter 4, every decision matters. Focus on maximizing your primary stats and survivability. The Arsenal is almost mandatory for the extra equipment slot. Consider bringing supply items from your camp that boost your core stats or provide extra healing.
Carefully manage your monster density. While you need resources, overwhelming yourself will lead to an early defeat. Use Oblivion to remove particularly dangerous tiles or to clear space for more beneficial ones. Ensure you have a strong economy of resources to keep your hero well-equipped.