This can all be summed up by a great military saying: "Amateurs study tactics, professionals study logistics."
If you can get the right troops to the battlefield at the right time, you should win.
The true "tactical" genius is one who can take a crap hand dealt to him and stun the enemy with the unsuspected. Within the R:TW game, there are certain things you can do to steal a victory, but these require timing, creativity, a little bit of luck, and a brain-lock by the AI (the usual state, so I guess just the first three things). It is best to avoid this situation altogether, hence logistics are more important.
If you haven't already, play some multiplayer battles. These eliminate the logistical aspect, and human players can come up with some freaky ideas...
Another great saying: "No plan survives the first contact with the enemy."
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