Lets look at the Pros and Cons of these 3 stages, which chars like them and which don't, and how they might contribute to the 5 starters in their own way by giving more MUs their potential "EVEN" stage, or by being striked instead of other stages so that we end up on another "EVEN" stage.
PS1
* Normal
Pros -
Cons - Bad edges
* Grass
Pros - Good for all, notably chars with good jumps and airials perhaps
Cons - Chars slow ground and air speed won't use this stage as well as others.
* Fire
Pros - Chars with good ground game, projectiles maybe, range, especially upwards ranged moves
Cons - Chars without escape abilities, without range and without ground game
* Water
Pros - Good for Chars with range, good ground game, and whoever is higher %
Cons - Air mobile chars talents are waster, some chars that cant approach/abuse windmill
* Rock
Pros - Chars with Good smash moves, good UpB, Good ground move speed (as rolling does nothing), escape capabilities (Quick UpB most of the time)
Cons - Chars without escape abilities, Chars that die up, chars that can approach talents wasted, doesnt matter here
Summary: A stage that chars with good ground game and good close range/boxing abilities will not strike, and chars that
are slow and unable to move around the stage may strike.
PS2
* Normal
Pros -
Cons -
* Electric
Pros - Chars with range, good smashes and multiple jumps or good airials with less than about 15 frames
Cons - Chars who rely on items/projectiles/grabs/ground game
* Flying
Pros - Chars with a good Uthrow, good airials, good air game and chars that like to jump really high anyway
Cons - Everyone who doesnt have good airials and good air game and anyone who doesnt like to jump really high
* Ice
Pros - Good smashes, good grabs, doesnt need to rely on spacing, good air game
Cons - Bad for chars that rely on spacing on the ground, perhaps also bad for chars with slow moves
* Ground
Pros - Chars with good range on the right, but mostly quite average for All
Cons - Fat chars, Chars that cant get away from the right side of the stage if they rely on ground game i guess
Summary: A stage that chars who have good air game, strong kills will not strike, and characters versing other chars that
they don't want to be in the air against or need stage control against will strike.
Lylat Cruise
Pros - Platforms benefit chars with good air game - Not complicated as PS2/PS1
Cons - Tilting, bad for chars relying mostly on ground game
Summary: A stage that chars with decent recovery, good air game and good uses for platforms will not strike, and characters
versing characters where they need to use their ground game as their biggest asset may strike. Also space animals and
other chars with bad recoveries and a dislike for tilted platforms may strike.
You don't just want the most viable stages in fairness/non randomness, as I've said before. You want to have stages that
to appeal to all chars, and stages that all chars are going to have something to strike, whether coz it's bad for them or
specifically good for the opponent. This will result in things getting striked for these reasons to come to the fairest stage.
After thinking about it I prefer Lylat the most because of how it covers a large amount of characters, and it's
all good for air characters and worse the more they rely on ground, so that's pretty simple and definitive.
PS2 is also good because it makes a similair impact, where mobility on the stage and ability to be in the air but still be safe
is good, and chars who need stage control will hate this stage.
PS1 seems to make the least impact to all characters. Lylat and PS2 both offer rewards for
mobility and good air game, and make it hard for characters that like to stay on the ground and have stage control, and other considerable character specific things.
PS1 however is favourable if you are playing a character that doesn't like to fight close range, or doesn't have good mobility.
Most of it's transformations are seperated, as in you end up playing on one side of the stage or the other, the only stage I find
doesn't have this is the forest transformation, so it benefits chars that work well in a small area, and might make it harder to approach them.
I think that because PS2 and Lylat benefit similair character traits, it would be a choice between them, because in your starters you want
"Something for everybody".
I think that Lylat is more definitive in what chars will like it and who won't like it, whereas PS2's stage transformations benefit a wider range of characters in one stage, and then hinder them in other stages, which I think makes it a bad starter, because it only appeals to the few chars that are advantaged on all of it's transformations. With PS2 I can't think of many MUs that would end up on that stage in starters. I can think of just a few for Lylat, and I admit it's quite close, but, taking into consideration Lylats edges (which shouldn't be looked at as "oh these are random", rather,
what characters are they hurting most/what chars can overcome them with a little care/what chars don't care), I still think Lylat is a fair bit more straigh forward to what characters are going to like it/not like it, and because there aren't any transformations it's a good stage for the same chars all the time.
Lylat and PS2 are rarely going to be played as a starter, in favour of BF, SV and YI, so I think it's more important to consider what chars will strike, what chars will never strike,
what chars will strike against other certain characters, and what characters will never strike against certain other characters.
In this case, I think Lylat is more straightforward and understandable in who will be striking/not striking than PS2. PS2 raises more uncertainty.
Also, with less experience on PS2, people aren't yet going to know what MU's they like it for or not until we learn it as a counter stage.
If you ever do think PS2 might just be better as a starter than Lylat for multiple reasons being weighed against others in favour of Lylat, that could be acceptable if plausible,
but I think until we all gather in-the-field knowledge about it with/against certain characters, it should stick to CP regardless.