I feel there are several ways to answer this question, experiance, education of staff and budget.
If unknown companies are fighting for a project, cost usually is the issue and the quality or experiance of staff perhaps are not considered.
If a company is offered a project on reputation then the consideration of cost is not neccesarily going to effect whether or not the project is won or not.
So the company bourne out of quality and a sound track record can afford to have educated Carpenters and Joiners, can charge more and have the time to present a well constructed project. Where as the other would have to be more cost effective.
This though processs would be concerned with larger and the more demanding of decking installations.
So to answer you question, to increase the quality of decking installations I would opt of only using educated and time served Carpenters/Joiners for my installations.