We have arguably more basic layer of abstractions which can help to derive the Maxwell equations. That is basic existence of charge (and vacuum properties - permittivity and permeability), theory of relativity (the special one) and math, which allows derivation of Gauss's law, Faraday's law, Amper's law. So if for somebody it's easier to understand the constant nature of the speed of light, he can explain Maxwell's equations from that.