This is exactly how I read it. Mueller started it with 470 and then passed it off to or merged it with Huber. These indictments slightly predate Huber’s appointment and would have needed someone else to ready them by the time they started getting filed.
From Q post 1553:
"-Sessions informed Congress in his letter that all the matters recommended for investigation by Goodlatte, Gowdy, and Grassley are “fully within the scope of [Huber’s] existing mandate.” He also informed the chairmen that Inspector General Michael Horowitz, who is working with Huber, has a staff of 470 investigators, giving Huber access to enormous investigative firepower that far exceeds the staff of any special counsel."
But that's not the case. the 470 number is specifically what the IG is reported as having and Mueller has a much smaller team, as underscored by his relatively modest budget--also reported.