Council, through its Districts, approves the MBCs but at least in our area, most of the MBCs come from units (i.e. are uniformed Scouters/registered adults) and are leaders, parents, Committee members, etc. from that unit. Yes, the Council approves the MBCs, but the MBCs within a particular unit are the first resources tapped to teach the MB to the Troop based on the annual plan/calendar that the unit approved. So yes, the unit doesn’t teach the MB, but the MBCs that are in that unit can and do teach MBs/lead the program the unit set out.
Also the units in support of District and Council are responsible for our own training, using the resources provided by National. In our Council, the District Training Chair utilizes the leaders in the units to track and encourage training in our leaders, like MBC training or Position Specific Training.
We have a new District MB Dean and he, along with his Council MB Dean (and the other District Deans) have really fixed our broken system in the Council - most MBCs were tracked at District by a Spreadsheet and they weren’t entered into any accessible database that the Scoutmasters could request information from when a Scout wanted to start a new MB and requested a Blue Card. The recent push to ScoutBook has alleviated that problem and makes it easier to find an approved and current MBC.
Our District MB Dean has not reached out to any of the units that I am aware of to see if there are any viable candidates to tech this new MB yet. I have an RFI out to him to find out what guidance, if any, our Council has put out.