Dhyer: P2 speed doesn't matter all too much unless you're Ulala and can actually pull off lapping people. Not giving the speed boosts... makes Maya a bit faster, comparatively, but not enough for a speed edge and probably not enough to catch up to Hallec.
Hallec (S3) vs. Maya (P2)
Okay. I'm presenting the argument -for- Maya here. Keep in mind I'm likely voting Hallec, myself (although this depends on testing of P2 status rates). Why am I doing this? Well, I know Maya, I like Maya, I like breaking her matches down.
1) You allow all Persona of the cast's starting Arcana. For Maya, that's Moon.
In this case, Maya pulls out Pariker, who voids all physicals except Sword in-game.
Counter-argument here: That's... not that much: Shot/Throw/Strike/Attack. Arguably axes would bypass, same as swords.
Counter-counter-argument: Attack subset encompasses a whole shitload of attack types, and Sword attacks are pretty much all sword-named or sword-themed.
Other options in this vein: Tsukiyomi using Trial of Darkness (High damage + ID. I need to test and see if magic does boost status chance, if it does this is turn 1 since it's 50% out of the jump, and allowing it to hit MDef would make it turn 1 anyway.)
My opinion: Unsure, honestly. >_> Tsukiyomi in some ways has the better argument.
2) You allow all Persona the cast have unique BEST compats with. For Maya, that's Moon, Hermit, and Magician. (Temperance, Fool, and the two Minor Arcana she gets are all shared, so.)
In this case, Rangda is a complete spoiler, no two ways about it. No other real options exist outside of him in these two categories except maaaaaaaybe a start with Genbu or other Hermit phys tanks and defense-buffing, but that's iffy as well.
3) You use 3.28x or higher as durability (yes, I mathed this out).
This reduces Hallec's damage to a bare 3HKO, which is all Maya needs.
Opinion: This is silly. >_>
4) You use her P2:IS form, which gets Tetrakarn on Artemis.
Opinion: If you can vote on it, well. (blah blah most people don't vote on unranked forms reminder since I'll get yelled at otherwise, love you all ^_^)
5) You allow P2 status to run off MATK/hit MDEF.
Opinion: The former's possible; might make her status, incuding ID, far more viable. However, running off MATK... I'll say right now that I don't think OK's numbers are right, in-topic; but if MATK does boost accuracy, then they would be more precise than mine, in which case a Maia Custom rush might actually work, especially leading off with Sleep -> ID'ing him out.
(For the record, I'm kinda against OK's numbers due to my own, admittedly sketchy, testing.)
6) You allow the ultimate weapon rumors.
This is the other logical way Maya can win. However, giving this to her... I can't see. Why? You can only have one Legendary Handgun. There are two people who can use it - Katsuya and Maya. Granted, Maya's the more logical user since the weapon also boosts SAtk, and Katsuya can get a pretty impressive weapon that's just a few points behind ingame and has a useful status for him (need to pull that up, it should be Silence). Still, it's got legality issues.
That aside, allow it and she has about 75% ID off her physical.
7) Alternate interp that I can't really gauge.
Opinion: Would need to be pretty good to allow the win.