There is currently a known limitation when using route imports that makes it impossible to to have a root route / be imported under a prefix without a trailing slash. See #4322 and silexphp/Silex#149

I propose to solve this problem in a generic way by offering an option when importing routes to remove or add trailing slashes (which defaults to null, meaning not modifying anything):

AcmeBusinessBundle_client:
    resource: "@AcmeBusinessBundle/Resources/config/routing/client.yml"
    prefix:   /clients
    trailing_slashes: true|false|null

This way, the users can unify the path on import the way they want.

So for example

acme_business_client_list:
    path:  /
    defaults: { _controller: AcmeBusinessBundle:Client:list }

imported with trailing_slashes: false under prefix: /clients will result in path /clients instead of /clients/.

The other case with trailing_slashes: true is helpful when you import third party routes without trailing slash but you decided that you app should use training slashes everywhere consistently.