We learned that portfolio managers can easily compute the optimal risky portfolio (and efficient frontier) for all investors. Thus, they economize on administrative costs (savings which are passed on...

We learned that portfolio managers can easily compute the optimal risky portfolio (and efficient frontier) for all investors. Thus, they economize on administrative costs (savings which are passed on to clients). Do you think that, in reality, all managers will derive the same optimal risky portfolio for their clients? What do you think the role of security analysis is in this case?