You can have countless good lane and team comps in theory, but it's when you're picking against opponents that you have to really think about your champ choices. Do we want to be sustaining and focusing on farm, or do we want to be forcing early game fights and trying to land those kills? Do we want to optimize AoE potential and shut down the entire team, or try a more systematic approach and focus on positioning to single out specific targets? One of the reasons I love draft against blind is that picking and counterpicking can greatly affect how a game will progress.
However, team comps can only go so far. The much more important factor is communication. Even in solo queue, a simple ping, call out for "mia" or letting a lane know that you're planning to come in for a gank can go a LONG way to maximizing team synergy and effectiveness.