methods for routes not getting generated

In my app the following routes definition

resources :organizations do
  resources :branches
end

produces

No route matches {:controller=>"branches", :action=>"destroy",
   :organization_id=>#<Organization _id: 4c589f81c0b2101cd1000011, ...>,
   :id=>#<Branch _id: 4c589f81c0b2101cd1000012, ...>}

when I call it like this

organization_branch_path(organization, branch)

whereas this produces the correct url without errors

organization_branch_path(:organization_id => 23, :id => 23)

Notably the output of rake routes does not include the method name for GET but I am not sure if this used to be the case in earlier versions. The relevant output of rake routes is

                    GET    /organizations/:organization_id/branches(.:format)          {:controller=>"branches", :action=>"index"}
   organization_branches POST   /organizations/:organization_id/branches(.:format)          {:controller=>"branches", :action=>"create"}
 new_organization_branch GET    /organizations/:organization_id/branches/new(.:format)      {:controller=>"branches", :action=>"new"}
                         GET    /organizations/:organization_id/branches/:id(.:format)      {:controller=>"branches", :action=>"show"}
                         PUT    /organizations/:organization_id/branches/:id(.:format)      {:controller=>"branches", :action=>"update"}
     organization_branch DELETE /organizations/:organization_id/branches/:id(.:format)      {:controller=>"branches", :action=>"destroy"}
edit_organization_branch GET    /organizations/:organization_id/branches/:id/edit(.:format) {:controller=>"branches", :action=>"edit"}

I think it used to work like the version where you just pass instances of objects before and not having to think about the names of the required ids.

I have to mention that I am using Mongoid and do not have ActiveRecord included in my configuration. Not sure yet whether you do any reflection on that end - which IMHO would not be required to generate and/or recognize the routes. You can just call to_param on all objects being passed in order of nesting and associated the ids by convention, right?