Id have thought a lane could sustain itself until level 4/5 which is when you reach level 6. Surely overwhelming force can have a large impact on a lane, i can understand ganking if a lane is behind and/or struggling, but surely ganking early just pushes the lane forwards and puts your bottom lane too far ahead and exposed to a gank from thier jungler, which seems counter productive to me. Im likely totally wrong, but I rarely see an early gank get a kill, or even be little more than a nuisance. I had a amumu gank me, combined with thier leona bot. Knocked everyone up (alistar lol), walked out, and they lost more total hp than we did, even though they had the advantage of surprise and 3 consectutive stuns. If that happened at level 6, when we had reached at least some element of complacency, that gank would have resulted in me dying, more than likely, due to the sheer volume of stuns.