According to the fans, here are how the matchups should go (from biggest mismatch to closest match). The rankings are based on the average score given to each hero by the contest entries:

+12 Statesman 24 over Snowslide 12
+10 Ms Liberty 22 over Lighthouse 12
+9 Synapse 21 over Tricksie 12
+7 Positron 21 over Serpent Drummer 14
+7 Infernal 21 over Regulus 14
+5 Mynx 20 over Pyrexiah 15
+4 Sister Psyche 21 over Aesir 17
+4 Lady Grey 19 over Polar Star 15
+4 Chain Reaction 17 over Fusillade 13
+4 Somber Warrior 17 over Flux 13
+3 Hero1 20 over Stygian 17
+3 Manticore 19 over Caldera 16
+3 Wasteland 17 over Radstorm 14
+3 Trajectory 16 over Bottle Rocket 13
+2 Night Strike 15 over Conductress 13

Some other interesting notes:

Freedom Quarter: 135 average points
Justice Quarter: 130 average points
Liberty Quarter: 132 average points
Victory Quarter: 131 average points

Clearly, the Freedom Quarter is considered the toughest section of the Bracket, with Justice the easiest place to advance to the final four.