Barocca, the same old thing I've been complaining about ever since I got here. :takes deep breath, wait for it....here it comes: Double click is run, not charge!! Yes, I know it says so in the tutorial but even back in STW units began to charge on their own based on distance to the enemy. Just click once and leave them alone, they will charge. If you make them run to the enemy the change over to charging speed is less noticeable. We had a very long discussion on this in the MTW unit guide thread, and in the beginner's guide thread, and in a few other threads. Suffice it to say the quick summery is thus: double click=run, but sometimes running is good, especially when using cavalry, because it gives them more time to get up to full speed and therefore full bonus. Double click is not charge.
Well, but thats how phalanx works.... And anyway, it might have been changed in RTW.

Actually when I doubleclick on an enemy they shout "Charge", and when I just r-click they shout "Attack".