no odes not make sens you are saying the same thing for both machines and weights which is practically to workout symmetrical muscles equally.
as far as training it depends if you are a beginner or not.
if you have some experience and you know what you are doing , then you can combine machines, weights, and cables. the problem with machines is that there is a wide variety of machines, some are useless or do not give you a good range of motion and are just there for people who wants just to train a bit and who are not really serious. however, there are machines that are designed for heavy duty bodybuilding and can replace weights and work symmetrical muscles equally.