There will always be people with different opinions on design, desicions on brand design in a company should ultimately be the responsibility of one person, this is the person you need to work with - everybody elses opinions on it are worthless - this guy probably has a preferred designer in an outside agency or beleives that in-house design is worth less than agency design (a lot of people in business judge how good design is by cost not aesthetics). Arrange a meeting with the person responsible for the re-design and talk to him about your concerns instead of trying to find sneaky persuasion tactics on forums