This is very helpful. Thank you.
But I would like to just add my opinion on the matter.
What I do in my playthroughs is... build all bakeries... everywhere.
It makes sense form a Role-playing point of view. Pendor seems to be bread drained. I mean, every town has a huge shortage of bread.
So I provide bread to the people of Pendor. That's why they support my claim to the throne
From a purely gameplay point of view. There are some benefits of this.
1) Bakeries make about 300-400 per week. Let's say 350 on average. This is about 200 less than the "optimal" enterprise. So for each bakery, you "lose" 200 compared to the best enterprise. However, 18 bakeries will cost you 85k, while optimal enterprises will cost you about 190k. This is a difference of 100k in the early/mid game. That is a big difference. Of course once you start building enterprises, having ones that make 550 means you start making more than if you build a bakery so the "effective" difference in cost is less than 100k. However, this is offset by the fact that you can build bakeries faster than you can the optimal enterprises.
2) In the end game, the theoretical total difference in income per week between optimal and bakeries will be 18x200 = 3.5k. However, you rarely collect from all 18. You are likely to be at war with one faction most of the time, sometimes 2. So realistically the difference will be about 2.5k. In the later part of the game if you are up against a "strong" faction with something like 8 or 10 cities, that difference is even less.
3) Sometimes wheat is really cheap (especially in Sarleon). Buying it when you there and leaving it in the bakery will mean the bakery makes more money.
4) When you get your first city, simply tell the bakery to keep all produce in the warehouse and every know and again sell the bread to the merchants in your city. This will reduce the chronic bread shortage and improve (I think it does) your prosperity.