As long as the combination of Mobby Meats + Mobby Meats Store offers more food than Butchery, it will still be a positive to spread the corp to the city, even if it isn't quite as efficient as Mobby Meats + Store + unreplaced Butchery. Butchery tops out at +5 food, and Mobby Meats will generate 0.5 food per copy of each resource, so that means it isn't too difficult to get better than Butchery from the corporation alone. If Mobby Meats Store was around +7% food rather than +4% per resource, then even 1 copy of 2 resources each would be +3 food from the Butchery, but +1 food plus +14% overall food for the city, a gain as soon as the city hit 14 food/turn from any other sources, which is not hard to do. An irrigated Farm is +5 food/turn by that time.
I think most cities by the time corporations start taking off should be capable of taking advantage of +% food. Cities start at size 4 (Pioneer) and unless they are drowning in unhappiness (which I will admit is possible) they can work a few tiles while at the same time raking in additional food from the corporation.
I think most cities by the time corporations start taking off should be capable of taking advantage of +% food. Cities start at size 4 (Pioneer) and unless they are drowning in unhappiness (which I will admit is possible) they can work a few tiles while at the same time raking in additional food from the corporation.