Even if you have already assigned to a team member all incoming applications from a client portal, you can always create more auto-assign rules by creating additional urls that are specific to other team members.
You have a template called 'Business training onboarding' and you've publish it as a client portal and assigned all incoming applications to Team member John Doe.
You can create additional urls for Team members Jane, Oliver, Michael etc... so that for each application created using their urls, the application will just go to their account.
To achieve this add the parameter at the end of your portal url: ?oid-XXX
So the url for Jane Miller would be: urlportail.com?oid-Jane%20Miller (since The browser converts spaces)
Share this url wherever you want. All files created from this url will be assigned to Jane.