It's doubtful whether the mirrors were ever all that effective, especially considering the effort required to produce, use, and mantain them in combat. The cranes were a ridiculous concept, though proper tactical excecution made them work well enough; mainly the support of a substantially heavy wall defense that on its own would be difficult to surmount.
Where Archimedes of Syracuse is concerned, the "law" is far superior to the "claw" - Archimedes' Principle, buoyancy, was vital in improving ship design and a host of other extremely useful things thru the modern age.