It surely is. Comparing how Ganon does vs Sheik / Snake is really just a matter of "how much worse can it get" though. Snake is virtually immune to ~90% of Ganon's moveset if he only knows when to crouch against what move. Every other of Ganon's move directly loses to ftilt 1, utilt and pivot grab. Kinda like Sheik with the chain except that Snake deals twice the damage in half the amount of time and doesn't need the "once he has the lead" to auto-win it. Not that it matters because he shouldn't beat Sheik but technically it's the "worse" match-up imo.
Not to beat a dead horse, since at the end of the day Ganon's still a terribad character who shouldn't win against both of these chars, but although snake's does more in a bulk, Sheik's ftilt lock (another really good damage racker) is capable of doing more damage in one "string" of attacks.
Not to mention sheik is really good at gimping ganon (at least compared to snake) because of her aerials (fair and bair especially), needles, tether hog, etc., so to me, it's really a "pick your poison" sort of deal.
The main difference is I think while sheik is capable of killing ganon earlier because of the offstage game and rack more damage to make up for it, Ganon in turn is able to kill sheik/mess her up more than snake because of her weak KO resistance/fall speed. Snake's probably the safer choice because it's much harder to punish ftilt1/utilt than it is sheik's mispaced things, but at the end of the day I think that at top play, the chances of getting hit for both are minimal