To counter that, as a former line manager if an employee just came to me and said he wanted a raise I could only give him so much consideration (big company). I

To counter that, as a former line manager if an employee just came to me and said he wanted a raise I could only give him so much consideration (big company). If he wanted to get more he'd need to have leverage like a competing offer so that I can go in to the HR team and be able to push them to give me approval to give him more and they would need to go their own managers to get that approval. Of course, said employee better be good at his job to get this treatment. If you are obnoxious or merely just barely good enough it will be an easier way to get rid of you than go through the hassle of big company firing procedure. Though I have to admit I never was in this situation as a manager, I did give fair share raises out of the pocket money I got to distribute as raises between my employees.