I think if we all co-operate we can eventually get all the categories of combo's together,
That said, Smash Attack should be simple, but we have:
Eight Spiker, Triple Wing, Cross Griffon (if/when legalised), and Triple Tiger (I guess?). Grip Base, Storm Grip, and SG Metal Flat (with an HMC). WD's 10 Wide, Wide Defense and Wide Survivor.
But then there are things using Fin Tectors with Driger F's shaft, or BK's casings +Wolborg 2's shaft, or heck, I guess even Uriel 2's tip (info is scarce on that, though).
We'd also have to work out if things were only good because of the conditions they battled in. Nolands combo, for example, has been mentioned by a few people to do rather poorly as we don't use weird hasbro finals stadiums.
(Also of note, Metal Ball Base w/4 balls is 1g lighter than HMC+SG Metal Change).
That said, talking about how hard it is is almost making me keen on taking the challenge, ahah.
Upper attack is relatively simple, but then we need more work on Driger V2's parts, and that specialised upper combo that sits in the middle of the stadium that beywiki mentions, and other stuff.