Here in San Diego we have 5 Congressmen
3 are Conservative Republicans and 2 are Liberal Democrats.
Both Dem dists are at least 75% or more democrat and
a conservative republican running against them would
be a slaughter.
Then the only successful strategy is to try to educate the voters in those two districts to the supremecy of conservative ideology.
But having a 3/2 ad is better than a 2/3 disadv.