rolling budget

sir taking reference from Technical article: All about budgeting – part 2

I wanted to know if we could find the values of DL by using the ratio of actual DL cost /actual revenue and then applying that using the sales value of following quarters to arrive at budgeted DL costs?? as we know that in case of rolling budget the following quarters preparation is made using the actual results.

Because the writer seems to be using growth rate of sales as growth rate for DL too, which is of course logical. But i was wondering if my approach would be marked correctly?

thank you!