In the case where there are a pool of resources to be allocated to a set of tasks, and it doesn't matter which of the resources performs which of the tasks, then it is often convenient to let the system choose the specific resource for each task. To do this,
add each resource in the pool to each task (see this section for how to do this)
set each task to be a single-resource task (see this section for how to do this)
The system will choose, for each task, a resource, such that the task is finished as early as possible.