If when dexterity = opponent agility the chance to hit is 100%; and each point changes this by 1%; then something is quite strange. I've had the following outcome in battle:
Polymeron 78/70.9 hit evaded. (Dexterity: 4.9 - implies enemy has 34 Agility)
Merc 59/58.56 hit evaded. (Dexterity: 7.2 - I don't know what the blazes that implies)
Merc 83/76.8 hit evaded. (Dexterity: 10.8 - again implies 34 Agility)
Merc 1/10 Block successful. - this shows the enemy had 20-29 Agility, because it had Block 8.
Enemy Armor : 26 - is this relevant?
Sorry for being a nag, but I clearly don't understand this well just yet...