Oh yes, that's absolutely necessary. That's how science works, right? Every new bit of knowledge builds upon older knowledge. It's theories all the way down, until we hit arbitrary axioms on which all our knowledge is based, though we hope those are somehow based on solid observations. And that's how we understand the world.
But just to be clear, I understand there's a colloquial meaning of "theory" as in what people mean when they say "that's just a theory". What I mean by "theory" is an epistemic object with either explanatory, or predictive power, or both. A theory can include multiple laws and hypotheses etc. And a theory "is just a theory" only until we can refute it, or find a better theory that does a better job at explaining things.
But just to be clear, I understand there's a colloquial meaning of "theory" as in what people mean when they say "that's just a theory". What I mean by "theory" is an epistemic object with either explanatory, or predictive power, or both. A theory can include multiple laws and hypotheses etc. And a theory "is just a theory" only until we can refute it, or find a better theory that does a better job at explaining things.