Matched contributions to 401k are generally
not considered part of total comp because there is no implication that the match can be converted into cash immediately, though this is often the case. Similarly, HSA contributions by the employer usually are not counted as total comp even though it is a form of cash benefit.
The rubric for all of these complicated and indirect forms of compensation is "benefits". These benefits are significantly limited in terms of practical cash value and rules around their use by regulation, whereas there is no bound on TC.