Well, the -1 came from the fact that we do have some things on Snake, to the point that we can make the matchup not ******** like Snake vs. a lot of other characters is.
I'm told by a lot of other tourneygoers that I have a stupidly large excess of patience when I'm playing, so I'm gonna go off a limb here and say you need to be really patient for this match. Staying in your shield, while keeping a "don't get grabbed" mentality can work wonders in this matchup.
We CAN reasonably camp Snake if we know what we're doing. With our stupid-*** rolls and overall general floatiness, the most we should be getting hit by are the grenades themselves, not the explosions. Staying airborne can work wonders on Snake's camp game, and if he approaches, what's he gonna do to you from below? Uair?
Some of your are probably gonna ask, "OMG BUT HOW DUZ LUCRIO LNAD!?!??!?" Here's a fun fact. Snake's Ftilt moves Snake forward slightly, and there's no hitbox inside Snake's body... so land inside Snake, like, literally so you're overlapping him, and spotdodge right away. Ftilt can't hit from that position, so the most Snake can do from here is dash away for a pivot grab, and you should have enough time to react to that.
Lucario also has the option to land on Snake's shield with ASC. Snake doesn't have much of an anti air outside of Utilt, and even then, it's awkward to use while he has his shield up. So, in essence, Snake doesn't have much of a response to it either. He either has to drop his shield and get hit(combo'ing into Utilt or Grab for free) or roll away, which is obviously a reset which enabled you to land. Problem solved.
When we consider characters who rely on getting fast punishes off on opponents who hit their shields with an attack, rapid hitting moves such as infinite jabs can really be a saving grace in that particular matchup. Now, Lucario is the only character in the game who is capable of starting a rapid in midair; ASC to be precise, and even though it has really low disjoint, Snake doesn't have anything to stop an approach from a 45 degree angle. So in essence, this is actually a very reliable approach.
Oh, and Fsmash is cool I guess. It's safe on his shield as long as you don't get powershielded obviously, and it can also blow up his nades without hurting you, so that'll add an extra level of protection in case he actually does powershield your Fsmash. And of course, I don't need to mention how helpful it is in catching characters with a poor ability to land, so go nuts with Fsmash, I guess.
The matchup is basically "be patient, keep your shield up, don't get grabbed, and ASC *****(?)" You'll notice all of that doesn't actually kill Snake, and considering he does have massive disjoint, range, speed, and power on us, he clearly doesn't have to put in much work, especially since he can punish with ease if mistakes are made on our part when the time comes to kill Snake.
Anyway, Lucario has the tools to deal with Snake, but Snake obviously has it easier on his end. So... slight disadvantage. This matchup isn't as ******** as MK.