If each task is a retrieval from the remote database, then the Loadup utility might be applicable. Loadup allows you to specify a set of dependent retrievals and then say 'loadResources' and it takes care of the dependencies. Each task is a separate proxy instance (whether of different proxy classes or same proxy class), and the proxy (or proxies) must implement the ILoadupProxy interface.
See
http://trac.puremvc.org/Utility_AS3_Loadup----Philip