Note that a procedure or any step of it has a "Resource" associated with it. You can specify a resource as a parameter, such as $[MYGROUP_POOL]. It doesn't have to be one of the fixed resources shown in the pulldown menu.
Then you can specify this parameter as one of the "actual parameters" on your runProcedure command.
The other thing to keep in mind is that the ectool runProcedure command will accept a --scheduleName parameter. So you can set up a (disabled) schedule that has all the normal parameters that a particular group wants to use to run your procedure, and then have them run the procedure as "ectool runProcedure my_project --scheduleName my_group_schedule".