I spent a bit of time analyzing this, and the end result that I saw was that it actually took me a turn longer to take Moscow because A) I spent a fortune on transports and B) I inevitably took the opportunity to kill the cut off the forces around Leningrad before they could retreat to Moscow. When I did get to Moscow, it was easier to take because I had killed those forces than if I had let them escape.
It has one of the same downsides as Sea Lion – you spend a small fortune on transports, which is that much less you have on ground forces in Russia. Don’t forget to watch out for the scramble from Leningrad! Those transports have to be covered.
If you are going to do this, instead of hitting Archangel why not hit Leningrad directly? You A) kill the Russian units there and B) complete an objective one whole turn earlier and C) are building at the MIC a whole turn earlier. Archangel only is only a 7 IPC swing, but taking Leningrad is a 9 IPC swing and therefore better. If you have force to spare, take Archangel at the same time (cause hey, same sea zone) and get a 16 IPC swing out of the move.
However, the best way is still to go overland and make tanks instead of transports…
Marsh