I would first look at your lease and see if it addresses additional persons being added to the lease if that is what your issue is really about. The tidyness of the living room seems to be masking what you are really asking about. Who pays the bulk of the utilities, would it cause an issue with parking, would it cause additional noise in the building? Are the extra people willing to have background and credit checks done? These would be some of my concerns as a landlord. Of course I am always interested in the condition of my units as well.
I'm not so worried as to whether or not the other tenants will be approved, what I really want is an answer to the final question. Would the described circumstance effect a landlords perception of their tenants even by the slightest bit, and in what direction?