Essentially the senior admins will focus on back end side of things more on the administrative level and assisting with managing the admin team. The community managers will be taking focus on the community side of things more while being that bridge with the admin team, developers, designers, and the community, hopefully adding more to the transparency and communication the community is looking for. From a power side of things the SA’s and CM’s are essentially the same just with a different primary focus.
@Roguecan correct me if I’m wrong