Knowing your high proficiency with Deadline, I totally expect that I misunderstood some of your question. More information about what you are trying to do, or maybe a hypothetical example would be useful to bring us on the same page.
In general, while the original implementation of Deadline had a Task represent one or more frames, this is really more a matter of mapping the values to whatever the Plugin needs to do.
For example, when writing a sequential video file, a single Task represents the whole sequence.
When baking 3dsMax textures, or simulating FumeFX files, a Task might map to a scene object, and it is up to the custom plugin or script to perform that mapping.
When rendering a single frame as Tiles, each Task represents a section of the final image, not a frame…
If there are multiple workloads that need to be processed in a specific order, you end up either with a single Job, single Task, and internal plugin or script logic that controls the order of processing on a single Worker, or you must use Job Dependencies to enforce the order of execution, allowing potentially different Workers to perform the various stages.
If your case lies somewhere between these two options, you will have to clarify, but it would be likely incompatible with how Deadline functions.