No, the Russian sub is there and gets to defend against the German sub (however, it can not be taken as a casualty from the Airplane shots), which means it gets to be taken as a casualty from the shot from the German sub, and it gets to shoot back at the German sub at a measly 1 out of 6. (also note that if the Germans are doing this attack, that means the bomber is not attacking Egypt)
Basically, its a very dicey battle, with the Germans shooting at 7 points of air and 2 points of submarine, while the Allies defend at 4 points and 1 point of submarine.
The Germans have a 17% chance of getting no air hits.
A 50% chance of getting one air hit.
and a 33% chance of getting 2 air hits in the first round (killing BB)
and also a 33% chance of hitting the Russian submarine.
Which basically comes out to this: 50% chance of scoring 2 hits in general
The allies have a 27% chance of hitting nothing the first round.
A 62% chance of sinking the German submarine.
and an 11% chance of sinking the German submarine + a German Fighter.
In the end, around half of the battles, Germany will only lose the German sub to a hit from the battleship, while sinking the Battleship and Transport AND leaving the Russian submarine alive. About a third of the time, Germany will lose a Fighter and a Submarine, but will also Kill the BB, Transport, and submarine. (TripleA doesn’t do a good job calculating this battle as it assumes that any hits from the submarine will go first to the Battleship as its first free hit, rather than to the russian submarine, which is what a good player would do)
But you have to remember, this is a very very dicey battle. Because the number of units involved is so low in number, it could easily get f-ed up very quickly. You could easily lose your submarine and fighter without getting a single hit. Yes, if you roll this battle 20000 times it will be only a smaller percentage of times that that happens, but it could so easily happen anyway.
(and yes, larry probably should have made that Russian submarine into a Russian destroyer for this reason)