Smaller manufactureres are at a design investment disadvantage to larger companies, capable of wasting money. By having a central design/research/development facility for several smaller manufacturing facilities the advantage goes to the more agile manufacturer, not just the larger manufacturer.
A more centralized design group would also be able to incorporate newer technology faster and better.
Websites, too, receive more care, expertise, and prevent problems if a webmaster quits.
By centralizing marketing, not only are the graphics better, additionally better deals for purchasing advertising.
Centralizing the design and marketing aspects of manufacturing are better with less agrivation.