Hi! I was informed via /r/smashbros that the finalization of this project will be happening very soon, so I wanted to give my two cents on how the Custom Movesets should be chosen for Mii Brawler.
If you want to know my history with Mii Brawler or want more clarification on my rationale, feel free to check out the Mii Brawler guide I created for the site:
http://smashboards.com/guides/super-smash-bros-brawl-er-a-mii-brawler-guide-and-analysis.160/
Considering that there are multiple potential tournament rulesets to fill, and that each slot can host any set of custom moves AND Mii sizes, the following eight sets should be considered for inclusion:
1122 Small [100% necessary]
2122 Small [100% necessary]
1132 Small [100% necessary]
2132 Small [100% necessary]
1122 Wide [100% necessary]
2122 Wide [100% necessary]
2132 Wide [optional but preferred]
1132 Wide [optional]
1111 Normal [if non-Customs]
1122 Normal [if Customs on, Sizes not]
2122 Normal [if Customs on, Sizes not]
1132 Normal [if Customs on, Sizes not]
2132 Normal [if Customs on, Sizes not]
TOTAL: 13
To get it quickly out of the way, I don't think X1X2 should be disputed. Onslaught is definitely the superior Side B option as Burning Dropkick has both redundant recovery potential with Helicopter Kick/Feint Jump and has more unsafe properties compared to Onslaught, and Headache Maker is simply not good. Feint Jump, on the other hand, practically makes Mii Brawler the mobile threat he is. There is no other comparable Down B option in terms of usability.
Sets 1122 and 2122 with Small are, simply put, the standard Mii Brawler set-ups. They provide the most mobility for Mii Brawler and include the infamous Helicopter Kick UpB special for maximum combo reward. The choice between Shotput and Ultimate Uppercut is match-up specific and/or playstyle specific, as both are good moves and have their uses. 1132 and 2132 Small offer much of what the first two sets offer, but instead focuses around Piston Punch for One-Inch Punch match-ups. These are less frequent than the standard variations' match-ups, but still very important and very different from the first two variants.
1122 and 2122 Wide may seem like complete redundancy with 1122 and 2122 Small, but there's a key difference in that
Short/Fat actually guarantees aerial combos that Short/Thin cannot. On a good deal of characters, for example, DThrow -> FAir -> FAir -> Helicopter Kick is a true combo string for Wide. The same cannot be said for Small. There's the drawback of jump height and mobility, but that's a choice for the player to make.
I recommend including 2132 Wide. 2132 Wide is super niche, but aerial combos are still easier to string with Short/Fat no matter what, even without Helicopter Kick. Added hitstun and damage is still a decent benefit if you want that. Also, 2132 is preferred over 1132 as Ultimate Uppercut benefits slightly more from Fat's added hitstun, and things like Jab1 -> Jab2 -> Ultimate Uppercut become easier to land. 1132 Wide is completely usable, but probably inferior to 1132 Small overall. Only add this if you feel the need to.
1122, 2122, 1132, and 2132 Normal are for tournament venues that allow customs but not variations in Mii sizes. They are not optimal compared to the other sets, but there are venues like this, so IMO there should be sets that are prepared to meet these rulesets.
That's it for me! Looking forward to finally seeing Mii Brawler in all of its glory soon.