CSMs
It's my understanding that BA has had difficulty in recruiting enough CSMs. Part of the problem may be the salary of about £26,500. (I can get the actual amount but I'd have to be back in the office to do so.)
I'm quite relaxed about this. If the pay is too low, then BA will have to raise it - it is a competitive market after all.
It should also be realised that BA really needs to meet recruitment targets. If MF is to grow, then there must a certain number of CSMs to manage the cabin crew. Let me pull some figures out of the air just for illustration. Say that MF has a target ratio of 1:10 for CSM:cabin crew. (It is not going to be 1:172 as we can have for existing fleets.) So, to recruit and manage 1,000 cabin crew means that 100 CSMs are required. A shortage of CSMs will therefore severely hinder the growth of MF.
As for under-employed EF CSDs: some may be suitable for the CSM position but none will apply because BA is not going to stump up an annual pay differential of £10,000-£30,000 to preserve their income.