jebus that (edit: further above post, have yet to read the other stuff) is soooo wrong.....
perfect example. pit olimar is even on sv (the most common neutrals). Bf is slightly pit with his good platform camping but it doesn't matter enough in this MU to really matter (due to giving oli more landing options) so lets say it's even too. now, pit destroys olimar on rainbow cruise and brinstar. pit decently beats olimar on halberd and delphino that are air based most of the time but have the down time (and in halberd's case the ceiling helps oli kill). he also has the advantage on olimar at lylat and has solid advantages on frigate orpheon. olimar destroys pit on castle siege pretty well. olimar decently beats pit on pks1 and has solid advantages on YI:B. it is slightly oli's favor at FD just to do to the fact that while it is big enough to give pit breathing room, oli still wins slightly here do to the lack of being able to even have aerial combat unless you are far offstage. the advantage is more noticable than pit's at BF's for sure so it does count toward olimar.
based on the overall stage list, pit has the overall advantage against olimar (pit has 6 advantageous stages, olimar has 4, there are 2 that are neutral). however, with the importance of game 1 in brawl, the chances are that pit will not get to have the MU advantage he should because even though pit solidly beats olimar stagewise via winning/going even on the majority of the stages, in game one pit is given the shaft because pks1, CS, FD, and YI:B make up 4/7 starter stages. since olimar is going to strike lylat (unless he is ********), the only stage pit is advantaged on in the "neutrals," that leaves sv and bf for pit to go even with olimar as opposed to having the advantage he should, but since oli will get to strike those as well, we are left with pit most likely getting a disadvantageous stage game 1 unless he gets lucky and they go sv or bf.
now for example, make like delphino a starter instead of lets say CS. now the starter list is FD, Pks1, and YI:B for heavy ground favoritism. then you have Delphino and Lylat for the aerial characters. then you have sv and bf which are neutral. while olimar still has a little bit of an advantage on striking by having 3 favorable stages as opposed to only having 2, that forces the process to make them go sv or bf and have an even first round instead of oli just having to strike lylat, sv, and bf thus forcing pit to play on a stage he is disadvantaged on (either CS, Pks1, FD, or YI:B) by a good amount.
that was just one example that i thought of. i can think of more like this too albeit the effect on the MUs will obviously be different (i.e. diddy vs kirby, wario vs ICs, TL vs snake, diddy vs g&w [this MU is drastically different on RC, Brinstar, main part of delphino].....). it isn't fair that ground characters get to have so much majority on the starter list with all of these heavy ground based stages as opposed to making it 3 ground based, 2-3 air based, 1-2 in between.
edit:
@lux
literally what is arbitrary? if it means what i think it does than no, it is very obvious what the difference between air based and ground based characters are.
ground based characters are characters who's move set is directed towards controlling your opponents position on the ground of the stage itself and trying to keep them grounded to so that they can use their on ground advantages. these characters however tend to be weak in controlling aerial position and have more weaknesses when in the air or offstage a decent way from a ledge. a perfect example of this is snake, who is god of stage ground control. while his opponents are on the ground, he has a plethora of ways to control his opponents grounded spacing and position thus giving him the ground advantage nearly every time. between c4, broken tilts with ridiculous range, damage output, and kill power, his heavy weight, dacus, and grenades, he has more than enough to overwhelm any character on the ground. however when forced into the air or off stage, his control is gone and now he is the one at a severe disadvantage getting his position and spacing controlled.
an aerial character is a character who's strengths lie in being able to manipulate an opponent from the air and being able to control the opponents aerial spacing and positioning. they try to keep the opponent in the air via juggling and punishing landings with moves that force them back into the air where they can control space. when fighting against opponents offstage who are trying to recover, they are the masters of preventing that and getting the kill/gimp or at the very least racking up lots of damage. also, they tend to not have to worry about recovering to the stage due to either having excellent recovery moves, good second jumps, multiple jumps, or combinations of all 3. a perfect example of this would be wario, wario owns the air with an iron clap. in essence all of his specials bar neutral are help his recovery if he is off stage and they all contribute to racking damage and getting kills even just when juggling/reading landings. combine this with his ability to weave through the air with near no restraint in his movement as well as his good set of aerial moves, his air game is near unmatched. however when wario is forced to play more grounded, his grounded weaknesses become glaringly obvious. while he still has options on the ground, they are not nearly as amazing as when he is able to use his aerial combat. his slower ground game gets him out ranged, out spaced, out positioned, and grab released.
now of course their are a good number of characters who have advantages in both categories and can fair well on both kinds of stages, but they all have some weakness or lack in their air or ground game that is exploitable when on a stage that is more based one way or the other. a couple of good examples are DDD and lucario.
DDD has a very strong onstage grounded game. he is not that powerful when in the air above the stage. however ddd does have a good offstage game with his large recovery, multiple jumps, and bair thus allowing him to have solid offstage options even though most of the time he is ground based.
lucario on the other hand also has a decent ground game with his projectile and range. also in the air above the stage his floatiness, range, power/combo-ability (or whatever you wanna call it) and air movement give a solid above stage aerial presence, i may go so far as to say one of the best there is. however his offstage aerial game is trash. his recovery is garbs, his second jump isn't spectacular, and overall he is much more susceptible to getting controlled, damaged, killed, and gimped when he is offstage.
hell another character with advantages in multiple categories would be g&w. he has great aerial game, great offstage game, and decent onstage game. in the air g&w has plenty of ways to **** on your day with his bair and nair and fair, not to mention how great his juggling game is with that uair forcing them to stay in the air longer. his offstage game is great too due to having a great recovery as well as good killing/gimping tools. then you have his onstage grounded game. this is where he is weaker for many reasons, but his pros tend to make up for a lot of them in many match ups. he is all around slow on the ground. his moves have bad startup times, and his grab range is rather lackluster. his dtilt is okay and his jab is nice but overall his ground game isn't super amazing. he is also a lightweight and thus easier to kill than many chars in brawl (this is alleviated a good amount though due to bucket brake). however, while slow, most of his grounded moves have ridiculous kill power, good damage, and make good set ups. his grab range may suck, but his dthrow sets up a dangerous tech chasing game that is nothing short of amazing.
whew that was a lot of writing. anyone else get my points yet?