Avast Ye! Howdy Darkwolf1601, If you are a level 23 witchdoctor, i recommend that you use some of your first companions. Dont mistake your starting companions as over rated because they are actually amazing! Have you trained Kan Po yet? I think that you should use Kan Po any other witch doctor companion and jack if you want to.
As for Lucky Jack Russel's Epics, I think you should give him relentless and bladestorm to get all those hits in! Yar! Honestly, don't take others opinions for your choice. I believe you should use whatever works for you and experiment with the different kinds of Epic Talents; find out which one works best for you!