[Legends: Arceus] Damage calculation

The basics if I'm right...
Fire pokes using fire moves does more damage than any other type using same move
Type opposite do more or less damage
Fire does more damage to steel and grass type pokes but less damage to water type pokes.

Sp.Atk effect the damage of special attack moves noted within circles in circles like a target

Attack effects the damage of physical attack moves noted with a 6 pointed star

Assuming I'm mostly right my question is this...

At what point would a sp.atk move with power of 60 do more damage than a physical attack with power 40 when physical attack stat is higher than special attack stat?

Would a sp.atk power of 60 with 100 sp.atk do more damage than a physical attack power of 40 with 120?

Do you add the attack power with the matching attack stat?

60 power with 100 sp.atk = 160
40 power with 120 attack = 160

Making both moves equally effective say water moves with water poke against a fire poke?

Making the only factor the opponents def and sp.def stats?

Assuming the opponent has say 110 in both def and sp.def would the moves then do the same damage?

https://m.bulbapedia.bulbagarden.net/wiki/Damage

After quickly glancing through, it doesn't seem to've been updated for Legends Arceus yet.
But, your post is correct up until you propose that the damage calculation is done by addition - that's incorrect. It's a more complicated formula than simply adding the Pokemon's base stat to the base damage of the move.

I don't specifically know the exact ins-and-outs, I just know it's not quite addition.

As it was, damage could vary regardless of stats; rather than a fixed damage output, there's a predictable damage range.
With that said, Legends Arceus definitely seems to have changed the formula for stats and damage calculation. It's noticeable right away; normally a Level 5 Starter Pokémon has about 20 HP. We get our starter in Hisui around level 10, but it already has 50+ HP. Furthermore, you can face a wild level 3 Bidoof, and it can still do sizeable damage to your level 22 Staravia (20~HP per hit), where in an older game it'd barely leave a scratch (2HP per hit).

So, all I have for you is a half-answer, but I'm sure you can find the correct one if you Google "Pokémon Legends Arceus Damage Calculation" or the likes!

I tried and got a lot of unrelated topics. Perhaps my Google search was too long so I'll try refining my search with less words in hopes to hit a few keywords with more accuracy. Thank you.
I did know it wasn't an exact addition at least in older games I stopped playing after diamond and pear.

Emerald and pearl being my main ones but Lost interest in the newer games until now.
I'm thinking of going backwards to sword and shield and see if they catch my interest like arceus has.