I think G&W beats Lucario much more convincingly than people are going to admit at the moment. Like...maybe the matchup could be considered near neutral if Lucario didn't just get DESTROYED by G&W's D-throw game. But the way things are, G&W actually does wreck Lucario pretty seriously when he D-throws him. The fact you can D-tilt to cover his techroll is really really powerful. I mean, Snake hates getting hit by G&W's D-tilt a lot due to getting F-air edgeguarded pretty easily. Lucario happens to be both lighter than Snake and equipped with an inferior recovery.
I'm not entirely sure about ZSS, but coincidentally, she suffers just as much to G&W's D-throw as Lucario does, except if she doesn't tech at all, she's also vulnerable to D-smash.
But anyhow, I kinda know how to fight Lucario. It's super boring as hell, but basically the idea against Lucario is he can't do anything to you if you don't let him. His air game sucks against G&W, and his ground game isn't exactly good either due to his lack of really quick pokes and bad grab range. He can wall a lot and his forward roll is an annoying escape option. As long as you stay out of his tiny shieldgrab range and don't leave yourself open to his forward roll while pressuring him, he can't do anything back to you. You basically just want to chip at him until you have an opportunity to safely juggle and edgeguard him.