This supposes team A has 10 C programmers in the first place. By one means or another, teams of web developers are put together and made to do non-web-development projects, and now half of the Windows 11 userland is written in fucking React. I'm not the one making these stupid decisions, but probably they were originally hired to work on a web project, then later moved to a new OS-related project because they were the pool of idle employees available, and the fleet of React-in-the-OS programmers expanded as new hires were now being funneled directly into React teams working on OS projects.