Knucklehead Fo´s are a pita and a nuisance, but any Captain worth his salt should know how to deal with them. You don´t have a right-seat-captain without a left-seat-FO.
Having a knucklehead in the left seat, on the other hand, is a real problem. CPs that will listen to an FO´s complaint about a problem Captain are few and far between. CPs that will take action are virtually non-existent.
If you hired
a liar, a cheat or a bigmouth
then be a man, own up to it and rectify it.