I'm currently playing the Marius vs Sulla scenario, with historical attrition option. According to the manual, my units should get replacements only if static for the whole turn and in a depot area.
I've run a couple of test turns and noticed that my armies always get replacements, no matter what.
For example, I moved Sulla's army, with a couple of crippled legions, from athens to thebes in assault mode. At the end of the turn, all my legions were back to full strength.
Am I missing something? This looks like a serious bug, as armies keep regaining their force even when on the run after heavy defeats, becoming de facto undestructable until replacement pool goes to zero.