Okay side note here away from above discussion:
Yeah I think the "ideal path" for the dlc is something like this:
-Reach Wild Area
-Trial 1 & 2
-Go do Milo & Nessa
-Trial 3
-You have a Kubfu now, go handle Kabu & go to Hammerlocke for the first time
-Return to the island and handle the Tower [effective end of dlc]
-Finish the game
-Finish the post game
-Return to the island and finish the content
You can do everything up to the tower at any time (& lord knows experience is not in short supply....) but are specifically locked from doing the G-Max Urshifu quest until beating the post game. But the way the levels up to the Tower of Water/Darkness work it feels like this is how its "meant" to be.
It's kind of making me think that Crown Tundra's main campaign will be design with around mid-game in mind, with the idea being that in a normal playthrough you would intertwine the Island of Armor through the first part of the game, "finish" it, then you intertwine Crown Tundra for the rest of the game, then circle back for postgame.
This is something that recently came to mind as I'm doing a fresh playthrough of Shield with IoA attached and trying to intertwine doing the Isle of Armor stuff with the main story. So based on this, if what you're guessing turns out to be true regarding Crown Tundra, then it'll be something like IoA intertwines with the first three gyms (the Motostoke circle), and then the Crown Tundra becomes accessible once you finish the first three gyms and then head to Hammerlocke and have to head through the northern half of the Wild Area, which basically means Tundra mixes in with the Hammerlocke section of the game.
I mean, to be more specific, if we look at the map of mainland Galar itself, we see the routes traversed across the game are divided into two different sections:
There's two different "circles" of routes that traverse the Galar main map that players travel through in the base game. Essentially, the first one that the southern half of the Wild Area connects to is the Motostoke circle, consisting of Motostoke, Turffield, and Hulbury, plus the two Galar Mines, and as you said, the Isle of Armor trials are seemingly designed based on the level curve to intertwine with the point of the game where you reach this circle and travel across it, like the first two trials and then travel around this circle to the first two gyms, then back to Motostoke, do Trial 3, then do Kabu and then go to Hammerlocke.
Then from there, there's the set of routes surrounding Hammerlocke, routes 6-9 and Stow-on-Side, Ballonlea, Circhester, and Spikemuth, and this segment is accessible from the northern half of the Wild Area. Based on Isle of Armor's curve intertwining with the first three badges, essentially the Motostoke Circle of routes, Crown Tundra will likely intertwine with the Hammerlocke circle as the player traverses across this part of Galar at the same time they explore the tundra. Based on what is known about Tundra, if it does end up being mid-game with this particular section, the "ideal path" for Crown Tundra would probably end up as something like this:
- Get to Hammerlocke and get the "Crown Pass" or whatever this will be called.
- Enter the Crown Tundra
- Likely Galarian Birds quest starts here
- Go back to mainland Galar, do Bea/Allister and Opal, then go back to Hammerlocke
- Return to Tundra, Regi quest
- Go back, now do Gordie/Melony and Piers, then eventually circle back to Hammerlocke (again)
- Again return to Tundra, and now do the UB quest
- Back to Hammerlocke and do Raihan
- Finish the rest of the game (ie the League and all)
This basically means the levels of the Pokemon involved in Crown Tundra and the main campaign will range from around Level 30-35 (Galarian Birds) to the third quest being around Level 45-50.
This is all pure speculation, but if what you're guessing turns out to be true, then this is a speculative (albeit likely) possibility of what could be the "ideal path" for the Crown Tundra segment of the DLC. Of course, this is a loose assumption, as the actual "ideal path" order will be based on what the actual level curve of Crown Tundra relative to the main game will be.
As is known the G-Max Urshifu quest and the final battle with Mustard are locked till the post-game, and I imagine something similar will be the case with Crown Tundra: the quest regarding stuff like the Birds and the Regis will be intertwined with the main story, specifically the second half of the main story, but the episode of Tundra surrounding Calyrex will likely be strictly post-game.
Also Hop post-game is involved in the Isle of Armor's quest for the G-Max Urshifu Max Honey, and the dialogue from Hop there implies that Sonia is in the Crown Tundra post-game. This suggests Sonia could possibly be involved in the Calyrex quest post-game, further suggesting Calyrex being a very important legendary with important connections to Galar history. So there's also that.
So in summation, this will likely be the post-game with both DLCs attached:
- Main post-game, Sordward+Shielbert weirdos arc with Dynamax mons and later catching Zacian/Zamazenta
- Isle of Armor G-Max Urshifu Honey quest (Featuring Hop)
- Crown Tundra Calyrex episode (Featuring Sonia)
- Also Isle of Armor Mustard final battle
Now granted, we have to wait a few more months for Crown Tundra to actually release to know what the situation with it is for sure, but it seems like this is what the path of the game with both DLC campaigns attached will be like, assuming Crown Tundra is available pre-Champion Cup. Just pointing this out regarding the level curve of the DLCs, given the way Isle of Armor was laid out in terms of levels, it's possible Crown Tundra will be laid out like this assuming you don't do it strictly postgame. Just some possibility to think about when Tundra actually comes out.