I don't think there is a good answer because you are pointing out a flaw in the writing of the films. Not a fatal flaw but one that irks true, long term fans of the Marvel characters. I think the real answer is that the writers and directors want to give everyone their moment and it is very hard to do that if you play by the "rules" of relative strength or power mentioned in the question.
Any villain that can defeat <PERSON> or <PERSON> in physical combat would kill <PERSON>, <PERSON> and even <PERSON>. And it would happen pretty quickly. <PERSON> can be killed by a bullet... and was in the comic world, lol. <PERSON> and <PERSON> laugh off bullets. So, yes, there are huge inconsistencies between "power" levels in the MCU and also at times in the comics.
The idea that <PERSON> had <PERSON>'s power when he was holding the hammer might be ok given prior stories. Certainly in the comics that has been true--- even if it is often a poor plot device--- it, along with the human alter ego of <PERSON>, helped Marvel reign in a strong character. It was <PERSON>'s kryptonite in many ways. In the MCU, <PERSON> says this in the first Thor movie. The problem is, the third Thor movie kind of gets rid of that. <PERSON> says to <PERSON>, "what are you, the god of hammers?" And the answer is no, the power has always been in him... 516
not the hammer.
So unfortunately, as good as the MCU has been, there are inconsistencies between movies. 22 films I guess it was bound to happen. If they thought these relative power things through, or wanted to, they could have been consistent. But they are after big moments and entertaining the general audience. The general audience does not care about this stuff. Half of them would be ok if an unarmed <PERSON> was able to trip <PERSON> with a kick, lol, as long as it looked cool or was funny.
One more thought in response to other's comments. The <PERSON> specifically stated in interviews after Infinity War that <PERSON> was not using the Power Stone when he trashed <PERSON>. So keep that in mind as you consider all the scenes with him fighting people like <PERSON> or <PERSON>. And that level of strength pretty much lines up with the <PERSON> in the comics.
If you were a general at war you would not send these less powerful characters against someone like <PERSON> directly. They might choose to do it anyway, but they would be hurt badly or killed. The shame of the stories is that none of these people really do get injured in these battles. Very little consequences for their heroics. I'd like to see <PERSON> with a broken arm and ribs after slowing down <PERSON> for a minute. But no, he just gets right back up. 516