As a wealth manager for a high-net-worth client, you are tasked with evaluating the performance of a multi-asset portfolio that includes equities, fixed income, and alternative investments. Your client has expressed concerns regarding the performance relative to a specific benchmark that they have selected, which is the 60/40 traditional allocation model. The benchmark is designed to represent market performance for a balanced investment allocation.

Your client has provided performance data showing that the portfolio returned 9% over the last year, while the benchmark returned 6%. However, the client is concerned about the portfolio's volatility, which they perceive to be higher than that of the benchmark, and thus, they question the appropriateness of this benchmark. Your task is to assess the suitability of this benchmark in evaluating the portfolio's performance and to provide a rationale for or against its use for performance evaluation purposes.

In your response, include considerations regarding the characteristics of the portfolio and benchmark, issues surrounding benchmarks in performance evaluation, and any recommendations for alternative benchmarks or adjustments that could provide a clearer performance picture.