The advantage in my opinion lies with Lucario if they use lots of aerial approaches. I play a friend on a daily basis who mains Lucario and try as I might I can't always avoid his down air, and this is almost a guaranteed separation for the IC.
Air Game: Lucario out ranges and out prioritizes the IC. Attacks like the IC Uair might have more priority, but Lucario can out range it with his Dair. I find it extremely difficult to counter Lucario when he is airborne, and his disjointed hit boxes can sometimes hit you when you are really not expecting it.
Ground Game: Lucario again out ranges IC on the ground, but I believe that the IC out prioritize most of his attacks (again I could be way off). I think that a Lucario with decent spacing can keep IC away from him with things like Fsmash (or side b?). Something I have noticed about Lucario (this might just be my friends play style) is he seems to have a difficult time getting past de-synced attacks. Things like short hopped de-synced blizzards are especially effective for keeping an approaching Lucario at bay. From what I can tell, it is extremely easy for Lucario to punish the IC because of the lag that most of their attacks have.
Edge Guarding: Here I think they are on fairly equal ground. Lucario has a number of attacks that either stay out for a while, or have weird hit boxes that can hit the IC when they try to recover or get up from the edge. On the other hand the IC have attacks like blizzard which (in my experience) is good for bothering someone trying to get up until they make a mistake. Also their belay can tether surprisingly fast, so if timed right you can ledge hog someone who isn't expecting it.
I hope this is the kind of thing you were looking for
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(Again I want to reiterate that this is in my experience, a lot of the priority stuff might be incorrect, but I am fairly confident in the other things)