As I see it the more reactive model of modship is the only really reasonable way to go at the moment. Not that I think that a mod shouldn't be proactive, but we're a big forum with a lot of content.
If my basic arithmetic doesn't fail me, we have over forty subforums here at ST, and the internal count says that we have 46,322 active members. Naturally, we don't really have 46,322 active members, but I'd say that the true amount certainly is over one thousand members, or even more.
To moderate all these forums and all these members we have ten people. Naturally this forces the mods to be more reactive than proactive, as it is impossible for the mods to actually monitor all the content that's posted. In fact, I find it odd that the system works as well as it does with only ten mods. Guess we are just that efficient.
In any case, if we want a more proactive style of moderating, I would say that more mods should be needed to even out the workload. Personally I think that would be a good thing.