Actually, if you are doing a northern reinforce, Karelia is the landing zone, and the key territory is West Russia.
If the Allies are landing in Karelia (or movng there from Norway), and can start moving forces into West Russia, Russia is MUCH better shielded than sending troops to Moscow via Archangel.
From West Russia, US and UK troops threaten the entire German advance, as well as their supply lines. It is a FAR superior position for UK and US troops IF the plan is to shield Russia. This of course also allows Russia to turn to face Japan’s advance… IF the Allies can get there in enough force.
The trade off with this type of strat is the length of Allied supply line. The US needs 3 turns to get a build unit to West Russia. UK needs 2. It also has Germany facing in one direction, allowing them to concentrate their forces better. The only way to prevent that is to make the occasional landing in Western, and that puts hiccups in the supply chain to West Russia…