is it pop or lvl that makes them attractive?
Both
Then perhaps a good idea would be to make it so that capitals don't capitulate until you have bombarded to society level to below 10 (or 5)?
If newbies weren't such an attractive target, they wouldn't even need scout defense.
That would help in the case of very new newbies. Now what about the guy that has just gotten to 10 nice little planets? We could weight the capitulation % to the size of the empires, that might encourage people to war against empires of similar size.
