Use your head here guys, there is no way Manziel comes here.
Think about it, we took a risk on Hardy, an infinitely more talented player than Manziel, it didn't work out and Garrett clearly wants him gone. You think Garrett, who likely knows he's gone if he doesn't make the playoffs this year, will be on board with signing a marginal talent like Manziel who literally has some sort of drama going on every 2 months?
No.
And you could argue that Jerry will just go off the reservation and do whatever he wants but I don't think that happens, not with Garrett and Stephen opposing, which I'm almost certain they will.
Griffin is another story because he doesn't have the off the field baggage although I have my doubts that they would want to bring in a guy who could be as much of a distraction as Griffin would be. It's definitely more likely than Manziel though.
Sadly I'm guessing Garrett being aware of his fate if we miss the playoffs will lead to him campaigning for a non-QB at 4 as well.