Help Please! urgent question from a new user..

Hi, I anm a Turkish national who has been offered a job and has to switch from tier 4 to tier 2. MY sponsor has issued me a CoS. However I am here with my husband as dependant. The problem is we will be applying together but we only have the money enough for the maintenance for both of us over the 90 days in his account not mine

As my sponsor is A rated I asked them to check the maintenance box for me but the CoS is already assigned and I am not sure whether they will be able to change this with sponsor note. In the else case, if they have to assign a new Cos, how long will it take? I know they wont be charged as I am Turkish, but still..I guess I have get on their good side in any case.

Thank you for your help..