Ooops. My bad. I thought this was an AA50 1941 question since you said Germany went first versus Karelia and you had never seen Karelia attacked. As for Spring Edition 1942 I cannot think how Karelia is not attacked and taken on G1.
Usually on R1 Russia hits West Russia (9 Inf, 2 Art, Tank) and Ukraine (3 Inf, Art, 3 Tank, 2 Ftr) with everything it can and depending on the rolls in Ukraine takes it or retreats their 3 tanks to fight another day. Either way that empties Karelia.
I guess someone might not go into West Russia heavy if they are willing to risk it and keep at least 5 infantry in Karelia. Add in 2 fighters and 2 infantry reinforcements that gives you 7 infantry with two fighters in defense max. Problem with that the Germans would certainly go all out to kill it and can easily.
As for Germany 1 I usually take out the UK/Russia fleet in SZ7 and the UK cruiser in SZ14 while counter attacking Russia in Ukraine and taking Karelia. I set up for a G2 attack on Egypt. I do not like the low odds battle for Egypt on G1 (72%) and I really detest the 2% chance that my battleship fails to kill the destroyer. I do not like battles that will lose me the game on Turn 1 if the dice go really badly against me.