The broader your knowledge the less coordination between people you have to the easier it is to Iterate as fast as possible.
Inter-person coordination overhead is a non-trivial for innovation and is often the bottleneck when trying to Iterate as fast as possible. The more a single person can cover in a vertical the better.
Rather than splitting work up vertically (e.g. design vs. dev vs. data science), split it up horizontally (e.g. person1 works on thing1, person2 works on thing2)