I'm sorry, i dont mean to sound thick or something but would this help the industrial city dilemma or would it be an entirely new commercial city?
He is telling you that you can fix your problem of low workforce, aka open jobs, in the city where you have industrial, aka factories, by having enough commercial to satisfay only about 40-50% shopers with goods. That way you can bulldoze part of the commercial zones(reduce jobs, reduce freight demand) and then instead of those shops build residential(homes for sims).
Ah okay thanks for the tip