Nnnno, this is a function of geometry, not explosive mechanics. Like, sorry, you're just wrong here lol. All an explosion is is an expansion of energy. If the energy is expanding in volume while remaining constant, what do you think is happening to its density?
I suppose you could argue that the explosion is retaining energy density despite increasing in volume because of magic ki but then you'd also just be arguing that the explosion's yield has nothing to do with Frieza's input at all.
Yeah, Cold is weaker than Frieza, who is weaker than Trunks, who is weaker(?) than Goku. Duh? Swords will cut things better if swung by stronger people. I don't know what your point is?