>>20324792Vulpix's strength in PMD as a starter lies in its Imprison/Confuse Ray to shut down difficult fights. That aside, it's nothing standout.
Eevee gets Adaptability and won't proc Run Away if it is the leader, which makes for a strong mon for main game given its only one weakness and movepool that is sufficient for the PMD series.
Pikachu gets a great offensive IQ tier, Agility for best buff, and Discharge for clearing monster houses. Pikachu is basically top tier in any PMD dungeon because of its amazingly solid level up movepool.
Treeko has the same IQ tier as Pikachu, get Mega Drain for endurance, and gets the Accuracy boosting IQ skill + Bullet Seed, which makes for one of the most damaging single moves in the game given how each hit is about as powerful as a normal attack. It also gets Agility. These make it very comparable to Pikachu, trading a room skill for a recovery skill and a boosted Bullet Seed. Most definitely top tier.
The starter I chose is Skitty. Normalize makes it unable to do any moves against Ghosts, but PMD has a wonky system where SE moves only do 1.4x damage, while STAB does 1.5x damage. Doing STAB is stronger than hitting things for SE damage, so you only ever have coverage moves for things that resist your STAB. This STAB on Normalize applies to its default attack (the free A button one), and it is also in a nice IQ that lets it get double attack for free. That's a free 3x damage on all mons that aren't Rock/Steel/Ghost. It requires more teammate use in taking out Ghosts, but it makes for an amazingly powerful mon that's consistent throughout the game given its great movepool that will always get STAB (room: Blizzard, range: Shadow Ball, etc).
Honestly, as long as you didn't pick Phanpy (no STAB, only non-Normal move is Rollout), you were fine. Most all the other mons get some nice thing to offer a team, and because you always have a partner, you can round out Type deficiencies that way. Vulpix just didn't stand out for me.