Yep, that worked perfectly! Carthage now has city plumbing (I looked it up and confirmed that Carthaginian houses often had private bathrooms with complicated plumbing), and cultured Romans can now go to the theatre.

Better still, a friend has given (yes, GIVEN) me a copy of Photoshop CS! No excuse now for not producing those Ptolemaic Egyptian troops once I've learned how to use the software - of course, that could take a while...