Wilde replaced Chief Officer Evans after Olympic's maiden voyage, yes.Murdoch did not miss a voyage but he also did the 2 day trial. Wilde joint after the Maiden Voyage.
However, I need to check further in that Murdoch doesn't appear to be listed on the 13 - 30 March 1912 sailing dept. crew list and all the officer positions are accounted for. If that is the case, then he missed the final Olympic voyage with Smith and Wilde.