This is a neat game! I like the concept of dice rolls to determine what buildings you can place. It's always fun to play a city-builder in game jams too!
If I understand right, the optimal strategy is fairly simple: always pick the biggest number you can and put the bigger number in the bigger area for more multipliers. I would have enjoyed more content (more layouts etc.).
I also think the main mechanic could have been incorporated to require a bit more strategy. For example, a bigger board but with domino-like rules for placement. So you roll two dice and that gives you a domino piece and you must connect them up to match.