Hey Sonya! These fires are a really nice exercise for exploring stylization! I think you’d benefit from trying to study the reference a little more before delving into the technical aspects of the exercise with materials, etc. If you can really boil down the elements of the fire you feel are integral to its representation (the underlying shape language, the motion, the ‘feel’) then you’ll have a much easier time making simplified but convincing effects!
Looking at your third fire, the base of the flames captures the curls and licks you’d find at the base of a fire, but I feel like the evolution of the particle shapes and the conical shape being created by your initial velocities as the fire moves up is betraying the ‘feeling’ of the fire you’re trying to capture; try finding some reference of similarly scaled fires and study the elongated shapes and curls that the flames create as they dissipate and the tension that exists between each lick of flame that pulls the forms together. If you can emulate these elements in the materials and particle behaviours I think you’ll have a really nice effect!