Problem 1 March/June 2018 relating to the proposed performance indicator

Problem 1 part c.:”Advise on appropriate performance measures and systems for Chiven when using the value chain approach to simplify the supply chain. ” in the following link:
https://www.chinaacc.com/upload/html/2018/07/25/hoe69365a0f3e249e39e3dfe8c16a0d614.pdf
The sample answer stated that: “Key issues in the current report and from the perspectives of running the physical stores are the number of employees and the floor space of the stores.Therefore, it is suggested that the revenue and operating profit per unit for each of these variables would be helpful and are also common indicators used in the retail trade.”
But I see that the Revenue per employee, Revenue per sq metre, Operating profit per sq metre in the sample answer are calculated using the total revenue and total number of employees of the company, not for store sector alone. Therefore, Revenue per employee, Revenue per sq metre, Operating profit per sq metre are for the whole company, not for store sector alone. So, there is fault in this sample answer.?
Thanks