That's a fair point, although it might also apply to some other pages with limited information. For research projects, each page could for instance have info about what they unlock, and each production bench and such can be tied to it by requirements.
But I'm kinda just throwing out ideas here. Sadly I don't have as much time to dedicate to working on wikis as I did a few years ago, so wholesale changes to templates and writing lots of content is probably out of reach currently. Stuff quickly takes on a life of its own, and once you start looking a bit deeper, there could be a lot of stuff to do. Feature creep I suppose, heh, or wishes creep.
In general, though, I prefer to have one page for each "thing". Makes it easier to maintain and update. And maybe easier for the end user as well, as opposed to pretty big articles. They're great, don't get me wrong, but it may be a little daunting as well with a tiny scroll-bar :P
In any case, having more details about research and skills in infoboxes/templates could be useful, whether they have their own page or not. But it's always a bit daunting to try to get to grips with templates. Often it's like a huge tech tree with one template calling another, calling another, and it's easy to lose overview. I've had a look at some, and may look into adding stuff. Am not terribly familiar with SMW, though. Sort of got that plants query working, eventually, but the pictures are gone now :/