I found a way. The only possible option (to me) was to have the enemy attack my southern group. I turned on the DDG radar and just let them come at me. The northern group has enough firepower to stop either the aircraft or the BCGN, but not both. I just had to let the bombers fire everything at the southern group so that they wouldn't unleash on the northern group. There are more fighters in the south and able to deal with the missiles.
This isn't quite doing it for me, but the idea is close.
Initially, I was annoying that the southern landing force had an Aegis cruiser, but the northern one didn't...until I realized that the ships in the Northern fleet do TEND to be more lower-radar-observable.
The trick is thus - don't let the northern force be detected! Make sure they are set to fire 'in self defense only' mode. All radars off. Don't take off too many fighters from them, and DON'T launch the helicopters. Just...sit tight up there, and move towards the landing zone. Most action to take for the first half of the mission relevant to that group is to send a few Growlers up from the nearby carrier to jam, if necessary (also, I fire off all the Tomahawks from the northern carrier and southern landing force at the northern airbase. Normally, that won't be enough to kill it if the Pyotr Veliky group can see what is going on...the Growlers help make sure that doesn't happen so the enemy northern airbase can be destroyed).
Then, all you have to worry about is the swarm of Tu-22s circling over the coast between the airbases. This is the tricky part - if they get detected, by
anything (including, say, the southern landing force or any aircraft including AWACS), they will flip their radars on. As soon as they flip their radars on, it's game over - they see the northern landing force, salvo off a hundred or so KH-15 Kickbacks, radio to the Pyotr Veliky group and another hundred or so missiles come from that direction, and...that's that.
So I'm finding that you really just need to make sure EVERY radar that could POSSIBLY detect that Tu-22 group stays off ALWAYS. If they get detected, by anything, anywhere, it's game over.
It seems easy enough to get the enemy attention on the southern group (which, as you note, is pretty easy to defend) just by shooting down the Russian AWACS that starts by them and putting up a huge fleet of aircraft over the southern enemy airbase.