I love Dorf and he is my main in PM so a new moveset for him including a sword was a possibility. Sense I have started playing Hyrule Warriors I have thought long and hard about this question, and I came to a conclusion that may sound weird. If we give Dorf a moveset inspired by HW he actually might not change as much as we think.
If you'll indulge me, I'll try to describe what I'm talking about.
Unchanged moves (Excluding the model now holding swords) : U-tilt F-tilt D-air B-air Neutral B (Grounded and Air)
If you haven't played or seen Dorf's moveset in HW I suggest you see a video so you can visualize what moves I am recreating.
Slightly Changed (aesthetically and/or functionally) D-tilt: Instead or his leg he jabs a sword. F-air: The sword adds a sourspot on the inside of the swing. U-air: He turns his body over perpendicular to the screen swinging his sword in an arc similar to his old U-air. Aerial Down B: He charges dark energy in his fists and plummets to the ground to create a burst attack on the surface. Forward B: Dorf lunges forward jabbing an enemy in the gut with one sword then slams the enemy to the ground with the tip of the sword. Aerial Forward B: Dorf lunges forward jabbing an enemy in the gut and then carries the enemy toward the ground on the tip of his sword. Aerial Up B: Surges upwards with Ganon's Shadow and attacks anyone in is way.
Completely new moves: F-smash: Does a violent turn around, swinging both swords forward. D-smash: Slams the tips of both blades downward on either side of him. U-smash: Drags both swords from behind his feet and swings them in an arc forward and over his head. Ground Down-B: Erratically swings his swords around himself leaving trails of dark magic along the slashes then bursts the magic outward around him. Grounded Up-B: Slams his open hand on the ground at his feet and then raises is, summoning Ganon's Shadow to burst from under him, clawing upwards.
I have one other idea to add to all of this so if anyone is interested in what Ive already talked about I'll continue.