If I ever face a PT, I'd leave Lylat so Ivysaur has a little more trouble recovering.... Just sayin'...
IDK how good are Squirtle or Charizard there, though....
Nah, Lylat's pretty good for PT. It's absolutely terrible for Charizard against character who can juggle well, but other than that, Ivysaur loves the platform configuration, and her recovery isn't even nerfed on it since it's a tether. Charizard is more likely to be gimped by the tilt than Ivysaur is. Squirtle likes it quite a bit too. It's also a stage that often gives PT lagless switches.
In any case, I don't know Lucario all that well, so my example may have been a little off (those strikes actually happened in a set though, but the other player was just picking up Lucario, so it may not be 100% ideal). However, it still illustrates the point. PT will definitely strike YI and CS. I'd be very surprised if Lucario doesn't strike SV and BF/Lylat. Even if FD isn't the exact median stage, it is still in the middle three.
But isn't it a super polar stage, unfairly geared towards "ground-based" characters? How is it that it can be struck third by two rational players, or even not struck at all? Yeah, if your thinking is "PT is above Lucario on the aerial-ground spectrum... Lucario likes ground stages more than PT does", you would think that PT would strike FD first. However, there is much more to consider than just that.
That would be mitigated by playing bo7 matches, no? We have deemed one-stock bo7 potentially competitive... why can't bo7 stamina be? Which CGs would become effectively infinite?