How important is consistency?

Should I ditch players w/ < a certain consistency #, so I do not waste time developing them?

Is Someone with a 3-5 consistency, good strength and good blocking (or tackling) worth keeping as an OL or DL?

I want high con for QB, MLB, SS but mix it up with some of the positions. A 20con and 1con WR is a good duo... Same if you use it for LCB/SS and RCB/FS. But depends more on the opponent and if I can substitute players. Against good teams, less low con... but a joker here and there. Easier teams can get a more varied look... but in the end... all play to their normal.