You underrate both Bourne, Meyers and to some degree Agular. Bourne had over 800 playing only about 50% of the offensive snaps and only 70 targets with a rookie QB. Meyers has been an excellent #3 he had 866 yds, about what you want your #3 to get and again with a rookie QB. I believe that with more snaps and more targets from a better QB in his 2nd year, Bourne can be much more productive.
And as for Agular, I don't think he ever got the chance to show what he can do. While Mac was being spoon fed the playbook, Agular spent most of this season running clear out routes for others to get open. He had only 63 targets all year. Not many chances to shine. With a better QB, I think Agular will get more opportunities next year. Remember with a mediocre Raider team he had 900 yds and almost a 19ypc average. He CAN get it done or at least get it done better next season.