This thinkpiece about superbat is pretty interesting to me, cause i can definitely see and try to understand it from op's pov.... but i can also see a batman who tops (well he is a control freak, and considering many of his canon trysts... at most he is a service top/sub top?), maybe a more versatile brucie, and maybe bottom bruce? (relating to 'real-self' kind of vulnerability & giving up control, as bruce. Not batman, not brucie, but just bruce wayne... but of course i can also see a top & dominant bruce wayne), while with clark, i can always see superman who tops i guess... but i'd also say that maybe superman wants to give up control too sometimes? He is the strongest man. He is a very steady pillar, many people rely/depend on him, the burden of hope and expectations on his shoulders can be quite heavy... but then what about him?? what about those times where he maybe wants- NEEDS to give up control? Maybe sometimes he needs someone to take care of him... someone who will let him be vulnerable, someone he can surrender himself fully to, someone that he trust enough to care for him, take control for/of him, take him apart, then put him back together.. maybe even spoil him? someone who will love him tenderly but also fiercely.. Or maybe sometimes he needs the hard/tough kind of love to help him feel more when all is numb... (So i think both batman and bruce can definitely top superman), and knowing how much control clark has to exercise on daily basis (cause what if he accidentally hurts someone?), the idea of bottom superman is also about letting him take, without the need to think too much about his own power/control... while with clark kent, i think he is a more versatile person, or maybe even someone who prefers to top? (service top or a dominant one, i think it depends on the partner)
So yeah... i just think that they are the two people who sometimes feel the need to give up control, but also feel the need to be in control (most of the time, especially bruce) I think that when you don't restrict or limit their dynamics to just one type (this is including outside of bedroom dynamic btw), you can explore them in depth while taking their canon personalities/traits into account... and there are many iterations of them, so there are many interesting ways to explore them in fics! Usually, i don't even think about bedroom dynamic that much, but well, have you seen superbat?!! they are one of those ships that i find pretty intriguing to explore deeply... Like for example, you could say both are a switch who prefer topping/bottoming depending on which 'persona' they're currently using at the time, and i think that's beautiful