I don't think Se has much to do with physical strength. I'm an advanced lifter by competitive weightlifting strength standards, and I'm Se PoLR.
I think @
niffer raises a good point that the dynamics you describe as Se are actually others taking care of you, which is Si ego or the caretaker romance style.
Se would be more about them pushing you to do something, pushing to get their way somehow.
I feel a strong imbalance with being taken care of by LSEs (but not so much other Si egos for some reason--I guess I just want to be taken care of in a Te way, not an Fe or pure Si way

). Like you, I hate feeling like they don't see me as their equal. I'm not sure what the solution is. It's probable that you actually also take care of them in a way (if you're close), but in a less tangible way, so it's hard to feel equal. LSE-EII duality descriptions in particular suggest that LSEs don't show appreciation even when they feel it, exacerbating the problem--they might think of you as an equal but just be bad at showing it.
You mentioned how you think you feel toward Gamma and Beta Se egos, but how do you think you feel toward Alpha and Delta Si egos?