There's no way around conflicts in the a-f-topic.
If you keep it the previous way, newbies will have a hard time getting used to the controls (which already happens enough in other places, say leftclicking the minimap doesn't work). Streamlining (at least) default hotkeys with other RTS will always be a good idea.
If you just make a the hotkey for fight and f for attack then ofcourse it won't make sense, but the meaning of the command names doesn't change (i believe that's what happened, and it's in my eyes the most comfortable way for everyone).
If you completely exchange fight and attack (that is, fight means attack ground and attack the previous fight or attack-move, a chance code-wise if you will) then current players will get messed up big time (although their hotkeys stay the same). They'd have to change the attack command to f and the fight command to a in order to have their play unaffacted. So for new players the hotkeys will make sense, but not for the current ones (and it would mean extra work).
Edit: Oh, Licho found a nice way to make sense of it :D