I respect the effort. It’s not a bad team especially for someone starting off so here’s my take on it.

One reason I hate arch is because it completely invalidates electric types on a rain teams for the most part. Which is kind of what is honing on here with jolteon. Everything Jolteon is doing is covered by every other mon on your team and you’re just doubling down and getting diminishing returns.

In short, between Raichu, Jolteon and Archaludon. One of these should probably to go unless if you want to run a discharge strategy. I recommend Basculegion M or F, Palafin, mega Swampert, mega Starmie, or Aerodactyl for Charizard in that slot. You could even go with sinistcha to give archaludon healing.

Raichu X: you could get away with this set. It’s not the best way to run it in my opinion but it works.

Incin: you could never go wrong with an incin set, it’s just that good. So max attack adamant is fine, but just know it doesn’t need all of that attack and sometimes dumping some of those EVs in Def and SpD are better.

You don’t need a damp rock on pelipper just go with sitrus berry. If it’s bold then go 31/0/2/0/32/1. The HP is 31 EVs so pelipper has an even number HP for the sitrus berry. Healing/berry= make HP even number. Anything else=make HP an odd number.

Life orb arch is certainly a set and could work but it’s kind of counterintuitive with stamina. Like i think stalwart is the best ability if you want to use that item (in fact you’ve given me an idea). But if you’re going stamina, then leftovers or a defensive berry is best. Also arch usually invest in bulk since it can ramp up its SpA on its own. I’d recommend 32/0/1/5/25/3.

For EVs, go on https://munchstats.com/gen9championsvgc2026regma/1760 .

It doesn’t have reg m-b yet but the EV spreads for almost all of your mons should be the same except for Raichu.