For me this discussion is pointless now. We clearly are going the same pattern as in Kongou Banchou. At the beginning Mel was stated to be the strongest then it was changed now he got his power back but we dont know his real power, the peak of his power. If we get some kind of numbers about Mels power lvl it will be only in his base form and that is all. Maybe Escanor is stronger than Mel in his base form but Meliodas has at least two more stages of power. Merlin knows only the power of Meliodas base form because he has never used even his demon mark form. Mel said himself that he returned a little bit to his old self so he probably still can not activate his demon mark form and next stage " darkness form". And it makes sense because he just have got back his power and like we know even if Nakaba gave us a bit informations about Mel, we still know nothing. Before we see his real power he has to learn how to use it and we are not even in halfway through story. Nakaba can not show us now that Mel is walking grim reaper with unparalleled power because this is not how he planned story. We will be getting more informations about Mel and his power step by step until the end of story.
Now about Escanor. He was hyped because he is probably the goddesses experiment, but he is still human and he can not be as strong as his creators because it would be without sense. Maybe he is container of their powers or maybe some kind of link to the world that let goddesses return. We know that demons and goddesses are equal. Experiment(creation) can not be stronger than creator

So there is limit to his power.
Well we know one thing. Mels peak has to be under 300k because he can not defeat all commandments. But is the sum of commandments powers really 300k? They had to be around 30k power lvl but it is impossible. There are weaker and stronger commandments. For me sum of their real power is beyond 450k because Zeldris and Estarossa have to be at least around 70k. So it makes sense why Mel even in his full power can not kill all of them.