That would be a good idea IMO, though it would kind of increase MM (energy). But colony management is all about MM.
Plus, when I said slots wouldn't be all too useful, it was in the respect that either we make ships take very long to build, or you can just build one per system and not get behind - I'm assuming we're going with a trekish approach of not having large ship counts in empires.
The downside effect of slots might be that you only build a few shipyards/fleetyards in your empire, and pump out ships from those few yards. That is, you don't need to build too many of them. Might not be a downside at all, depends on what you want with the game. Maybe restricting shipyard construction to systems with Raw Materials (and/or Dilithium might be pushing it) would help in this case. Sure, losing such systems would be crippling, but then again, one more reason to protect those systems with all you've got.
