It really boils down to how much production are you doing? What scale - large (cabinet boxes or doors) v. small (trim or intricate pieces)? Oh, and how frequently? If you're sanding large blanks for several hours a day, it's could be argued that you'd save/create some time by having a larger pad. Larger sander is also more cumbersome. Perhaps not by much, but they are.
After more than 20 years in a finish painting environment, I'd honestly prefer a good edge sander paired with a separate 125mm x 3mm stroke. For my applications, I feel that provides me with the best overall efficiency.
To answer your question, I think 2 pads are appropriate, but a matter of size and style is really a matter of preference that only you can answer.