To add to this, now that I'm considering it, I really don't see the need for five starters. Three is fine given the ones available. Here's my reasoning: Smashville can be considered
the neutral stage. It is the perfect medium between Final Destination and Battlefield. Players will typically want to either go to either Battlefield, or Final Destination, but not both, while still being okay with Smashville as the alternative choice. So let's give some scenarios:
Player A: Wants to go to Battlefield preferably, but is fine with Smashville.
Player B: Wants to go to Final Destination, but is fine with Smashville.
Player A gets the first ban. They ban Final Destination. Arguably this gives Player B the advantage, but because Battlefield favors Player A, and Smashville is at worst a fair choice, Player A won't lose out by picking first.
Player B bans 2nd. If Player A bans Battlefield or Smashville, they get what they want. If they ban Final Destination, at worst they go to Smashville.
The tl;dr of this is that a lot of times games are going to wind up on Smashville. From a variety perspective, this might not seem very pleasing. But it is infinitely better, in my opinion, than having two Smashvilles in our starter roster, and one that heavily biases certain characters.
Also, let's face it. People usually go to Smashville anyway.
I am unconvinced that the imperfections of Lylat outweigh the serious striking issues of having only 3 starters.
Keep in mind that almost no game 1s are actually going to end up on Lylat if it is a starter, least of all in a matchup it skews--anyone who cares will strike it.
For most characters, this makes zero difference.
Then you have guys like Little Mac, where Smashville and Battlefield are two of his worst stages. (But T&C is one of his very best, and Lylat is pretty good too.)
Well, I just laid out why there aren't serious striking issues by only having three starters. But I think the fact that you just said that no one is going to actually go to Lylat outlines the fact that Lylat as a starter
is a problem. And it does make a difference because it means that someone is going to have to waste their ban on it, depending on who gets first ban.
Also, I'm not convinced Little Mac enjoys Lylat. The stage layout is nice, but it hurts his recovery even more so.