Not sure that I understand your question. These are T5 MFA belts sold especially for MFA pulleys to which you referred so yes they are compatible. As for being too tight around the axles, that all depends on how far apart the axles are. Check out the calculators tab for a calculator to check on distance between centres. You then need to make sure that the pulleys do not clash if the distance between centres is too small. Simply take the overall diameter of each pulley, add together and divide by 2, this number needs to be smaller than the calculated distance between centres.
So in your case, the pulleys need to be greater than 32mm apart but the calculated distance between centres is 37mm but I doubt if you will get the belt on very easily.