An important caveat to such a comparison of course is that medieval theories were much more qualitative than quantitative in nature.
But while string theory may purport to offer scientific solutions to scientific problems, we all know that no purely scientific theory can ever offer anything approaching a solid metaphysical foundation.
Thus any proposed or purported metaphysical majesty for string theory would be limited at best.
If you are a student of physics you will be well aware of the string theory.
It first came into use in the 1960s as a method of understanding and explaining the nuclear force theory.