Have you ever queued at the border or at an administration to see a large amount of people go through a very inefficient process? It can take ages for you to get what you want and you'll have to come back again if there's anything missing in your files.
In a small team, think 6 or 7 people, processes are smoother and proximity makes working together much easier. So rather than having a large and segmented team across multiple offices, chances are that smaller multidisciplinary teams will do much better.
When people have different backgrounds and work at the same place, they learn from each other and tackle problems with creativity and efficiency. All team mates are working towards the same goal and that makes collaboration highly effective.