eeeeeeeeeeehhhhhhhh you have to be a god janna player,
Morgana on the other hand is a good pick. That being said, it doesn't really matter regarding counter picks. A good duo queue, with amazing synergy is leaps and bounds against whatever you are facing. If you pick a good, cheesy strat, or a are just able to out play the enemy because of better communication, 9/10 you will succeed in ranked games, because lets be honest, you facing new people every time so its not like they will know what your duo will do.
After dominating bottom lane, getting tower, getting dragon, getting mid (travelling there to pressure earlier), your team should have a lead. From that point on, its about whether your team throws or not, but that is just solo queue. But you can definitely increase your chances by controlling the bottom half of the map early one.
Also, what I find can win alot of games is over extending bottom lane with your support, and warding really well. If you win the lane hard, you can start pushing the second tier turret, and force the jungler and mid to come to you. At that point you just run back, and keep repeating, removing pressure from top (jungler will always be bottom) and removing pressure from mid (if you are ahead, you can easily 2 v 3 enemy botlane + jungle, or kite backwards etc, their mid has to come in order to kill you/make it worth while, but if you ward well, they will never be able to get to you) .
As for jungler camping bottom, if you ward properly, and the jungler come and you have to play passive, you are already winning. (less pressure across the map, more pressure for you team as your jungler will be ganking other lanes). Of course you can argue that your mid and top will still feed, but that solo queue, and duo, solo, etcetcetc won't change that.