Kick Off Workflow Tasks from a Form
It is possible to "kick off" workflow tasks for more than one user from a form. The HR or Finance person fills in the form and selects a user(s) to send the task to. A task for the workflow will appear on the Task List of the selected users.
Let's take a look at a simple example first. You want to create a form that launches an Employee Review workflow task and adds them to the employee manager's Task List. The form is executed by an HR employee when Employee Review time comes around.
This example form contains the following:
It allows you to trigger the flow for a different user or role when you browse the flow URL. In your case, I would recommend that you create a separate form with all the basic information fields in it. Then add a field where the user filling in that form can add the list of users for whom he wants to start the flow. Then create a business rule which uses http.get method to call your workflow URL. You will have to call this URL multiple times depending on how many users you want to create the task for. And you can pass the usernames of those users and basic information data to the flow in this URL by using _data URL parameter.
Field Budget Workflow