'winning all fights is not the highest achievement ; submitting the enemy without fighting IS the highest achievement'.
It made me think it was not absolutely true. In my opinion O Sensei created Aikido for an even higher purpose that could be summed up this way : 'making a friend out of your enemy and restoring general peace is the real achievement'.
Depends on how you accomplish that. I personally don't think that the statements are different.
Fighting is about getting your way. If you win without physical combat, whether you've made a friend of your enemy or not, you've fulfilled the goal mentioned in Art of War.
Accomplishing the friendship in addition is a bonus and I don't really think that Aikido necessarily advocates that, although it is a nice plus and something we say is desirable.