Strangely, SAS and China Eastern haven't teamed up yet. With CE already flying into CPH and starting the PVG-ARN route on June 22nd, you’d think a partnership would be a no-brainer. As of now, though, you still can’t book them on a single ticket from either SAS or CE.

Also under the current conditions, SkyTeam effectively controls the “shortcut” between Europe and Asia via ARN and CPH through partnerships with Chinese airlines. Helsinki once served as the primary gateway, but Finnair no longer dominates that role. Additionally, with oneworld having very limited presence in mainland China, SkyTeam is well positioned to become one of the most efficient and integrated options for fast travel between Europe and the region.

It would definitely be ideal and certainly not impossible because both MU and SK have good relationships with AF-KL.

MU actually has a JV with AF out of CDG.

SK seems to be dragging its feet a bit on Skyteam integration, just a bit of an outsider observation. There are far more LH-codeshares than I'd expect for a Skyteam airline, and SK often won't sell AF/KL metal. As mentioned, there's a lot of opportunity for SK to sell link to MU at both CPH and ARN.

HEL is still very dominant, the issue is laying over in HEL doesn't make any sense any more given flight routes and timing. HEL used to be one of the fastest options to Asia but it is now one of the slowest. AY flies to countless more long-haul destinations in Asia than those available from ARN or CPH. Both CA, TG and the ME3 fly from both CPH and ARN to Asia with plenty of inventory. You can make this argument perhaps for China but not for Asia. From ARN, I can fly to PEK on CA and PVG on MU when they re-start that route which is hardly dominant.

I struggle with the routes SK will sell me AF/KL tickets on and which they don't. Staying with the Asia example, they'll resell AF/KL to BKK when their own flight it out of season but they won't sell KUL or CGK. They will sell me ICN on AF/KL metal and NRT on KL metal but not MNL etc.