Yeah, I agree. It's the cumulative power you have on that base divided by 5. So 12 power gets you 2 points, 15 power in any combination of power number cards gets you 3 VPs etc. There aren't too many single cards that are worth 5 power, so even if you had 1 from each faction you combined, that's only 2 extra points and kind of a pain to pull off.
Pirates can really clean up on this one. If this base is out and you have lots of minions on the board and Full Sail in your hand...Wait for another base to break and move everything to the Factory. I scored 9 points in one go that way. It does leave the board empty of your minions, but there are at least two new bases, so other players will not have that much more out,
I don't think it needs to be confirmed by AEG, Scott. They are pretty clear when they want to differentiate and they do not say "for every minion with power 5 or higher" - which is certainly how they would write it if that was their intention. Also, with a power of 25 required, it's feasible that someone could easily get 2-3 points, making it a powerful enough but not too powerful base.