On the Scrooge McDuck vs. Shovel Knight:
Scrooge McDuck has the experience, wealth, power, and tactics of an old man, but Shovel Knight's youth, magic, and tenancy will play out against the fight, as Scrooge has faced Magica de Spell several times when she stole his lucky dime, but she is weak compared to the Enchantress and her Order of the No Quarter, so that's one factor, as well as the wealth Scrooge accumulated is small to the vast amount of gold SK collected with Shield Knight for years, 2 quadrillion to 5.7 to 100 quintillion in gold, jewels, and other riches according to the beginning of the game. (which I haven't played tbh, so I am shooting spitwads into the wind here)
Did Shovel Knight have a quirky pilot to fly to other parts of the map in SK, fuck no. Scrooge has, Launchpad McQuack, which he did sided with Darkwing Duck, but that's another thing later on down the road.
Ok, so Scrooge did face Superman, so what? It was lazy, fucking lazy writing on Scrooge's part.
Also one other thing to play other that they shared in common: Their arch rivals (Victor ((or Hugo)) Glomgold and Black Knight) to build up their character traits down the road.
Weapon wise: Canes can only do so much in blunt force tramas, but shovels can actually kill with both blunt and sharp edge attacks to the head and body, so there's a factor to that. Shovel > cane. Look at Australia's way of trying to control the Cane Toads epidemic, they have a better success rate with a shovel than a cane. (poor animals that died biting the backs of the Cane toads...)
... Ok, so Shovel Knight hasn't been on the moon like McDuck has, but he has survived the pressures of the sea with nothing but a suit of armor and luck on his side, so I'll give Scrooge that.
I need to stop over analyzing stuff that I don't understand, because it will come back and bite me in the ass.