I can't access a placeholder-prefixed route because of a conflict

Here are the routes I'm working on (generated by apiResource Laravel's method). As you can see, there are 1 or 2 placeholders. My issue comes when I try to GET anything/customers. It raises this exception:

Missing required parameters for [Route: json-api.customers.show] [URI: {tenant}/customers/{customer}].

Unless I'm missing an obvious thing, the router should accept this request because anything/customers matches {tenant}/customers.

I'd really appreciate any help about that. Thanks in advance.

via Chebli Mohamed