It was built by him and his staff.Building a team isn't taking in a bunch of transfers to fill out your roster. There's a world of difference there.
College programs are built over time. With recruiting cycle over recruiting cycle. This Colorado team here is coached by Sanders but it wasn't built by Sanders.
I agree w/ you though, it takes a few years to really find your groove w/ coaches and players and the needs you really have for your conference.
Although Deion was at CU pretty early before the start of the season, there were a lot of Blue Chip recruits that were already being groomed by other top programs. Now he will have an even better pick of the talent out there. The season after that, the same thing.