An MA is in no shape and form an MBA. Hence why it's pre-experience. It would certainly help to have one when applying for MBAs, although in all honesty you would be better off with something like an MSc in Finance.
An MBA may well cover many of the topics of an MA, and as such complement it in the sense that you have a head start, but they're very different kettles of fish. I recommend you read the literature on both MBAs and MAs, and do a little thinking around why these courses aer pre- and post-experience.
Hope this helps, maybe google can be of further assistance.