The level is a big factor when it comes down to calculating the chance to hit (which can easily be verified with the help of a henchman). Lvl 20 archer with 100 offence point blank vs a lvl 22 char with 189 defence: chance to hit 37% Lvl 22 archer with 100 offence point blank vs a lvl 22 char with 189 defence: chance to hit 61%
It is worth noting that the defence of the archer increased from 105 to 113 as well.
