unit info attack disparity

[lordgeorgr141]

while looking over unit stats i realise that there is a huge disparity between what the unit cards states on the custom battle unit selection screen and the unit cards while actually fighting, eg. some line infantry has 8 melee attack while on the custom battle screen but on the unit card during the battle it states that it has 18 melee attack. looking at the unit stats in db it appears that the "8" attack is correct, but then what is causing the +10 attack difference?

[Steph]

Can be several things. Experience. General bonus. Maybe a tech