Most RTS games out there put you in the role of a General. Company of Heroes puts you in the role of a Captain.
If you DO try the old build up and assault strategies, you'll find yourself without an army halfway through to the enemy base (if there is a central base). Snipers and Machine Gunners can wipe out entire infantry squads in a matter of seconds, mines and artillery emplacements can take out a whole line of tanks just as quickly... It's all about strategic positioning, and I think I speak for the whole nation of RTS fans when I say we were dying for this feature to finally come into the spotlight.
The end result of a battle will (for I guess the first time in RTS) be almost entirely dependent on your ability to lead your troops. No matter how strong the opposition is, it can be countered, and in many occasions by the weakest of troops. If well covered, an infantry squad can destroy a Panzer tank. If well placed, a machine gun crew can hold off the enemy advance long enough for reinforcements to arrive. It's all about finding the proper cover, establishing command posts in key locations, and knowing where to place each type of soldier so they can be of greater use.
You truly are a Captain in this game, not a General. A General leads through his lower officers, as a Captain deals with issues directly... In COH, you deal with the details, you follow your orders through, by the blood of your men, the true responsible for winning a war.