My team's structure is also this dualistic approach that you are contemplating. Our team is split with a build team (this includes all fabrication, prototyping, design, etc.) and a business team, which handles presentations, sponsors, and all PR. For our team, it works pretty well, provided that the captains constantly communicate.
As Brian mentioned, splitting a team like that does have its downsides. Sometimes kids have no idea what the other side is doing, and in that case, we do every once in a while have giant team meetings where all the captains give updates. But it is definitely more flexible to have a dualistic team. During the build season, when we (the business team) work on Chairman's or the executive summary, we work off to the side in our workshop while they build on the other side. At competitions, the business team not only talks to judges and visitors, but we also try to talk to scouts rather than distracting any of our build kids. We also give the build team crash courses in our community outreach so they know what we do to a small degree as well.
Another thing to watch out for is making kids feel limited to only being able to do either business or build. While it usually works out that someone only wants to do one, we do make sure that our kids know they can do both, if they're willing to put in the time.
Good luck with plans and if you have any questions about how my team works, feel free to ask! I've been a captain for the past three years, but I'm an alumnus now
