So when goku fought beerus originally wasn there a line implying that if he and vegeta fused they wouldnt be strong enough to fight beerus.. so he became the original red god form. So by that "logic" red god form stronger than fusion of goku and vegeta at that time..... so we also know blue god is stronger than red god.... So now these 2 chicks, who are still trying to become a SSJ3 period, fusing ...which should be weaker than goku and vegeta back when super started in the first place... are stronger than goku in blue form?
So by this logic they are the strongest base characters in the entire series right now. Fantastic.
You are forgetting the green hair and such meaning that Kefla turned into a Legendary Super Saiyan, which surpasses all Super Saiyan forms except for Ultra Instinct.