While developing this strategy, it became more of an exercise for me in analyzing the efficiency of my distribution network and in careful planning of city growth. As such, it was extremely instructional to me and, I believe, pretty successful. I was able to grow to 1480 population and a high prosperity rating with only the two housing blocks, one in each of those two areas. Whether or not this is a viable approach to completing the level I'm less sure of. I definitely plan to take it from here, and will probably post the result as soon as I can.
The zip file includes 3 saves, labeled Lugdunum 1, 2 and 3. These represent the city at population levels of 500, 1000 and 1480, which is as far as I was able to take it without going past my initial 72 tiles of housing. I would love to receive any and all feedback on the approach I've taken, either through the forum or e-mail.