He wasnt the general however. He was primarily an administrator who recognized talent and knew how to govern. He may have made some battle plans but generally let his officers do that.
Not so. Since the beginning of his career until the last campaigns conducted under his rule, he took part in the vast majority of them. That can be proven for instance, by a simple look at his posts he took up show that in time of peace he settled for being an administrator of some sort, while in periods of conflict, he was given military rank. (Which meant from there on that he had to take titles which implied political significance over military ones).
- In 184, he took part in the campaigns against the Yellow Turbans as "Chief Commandant of Cavalry"
- From 185 to 188, he campaigned nowhere.
- In 189-190, he took part in the in the Coalition against Dong Zhuo, leading his own army, under the rank of "General who Displays Firmness". Throughout this not only did he lead his own army forward he also repeatedly offered council on how the coalition's army should act.
- In 191-192, he wandered the land raising troops for his army until he assisted the governor of Dongjun against bandits. He then became Governor of Dongjun. Still he spent quite some time going with his army to deal with the bandits around the region.
- In 193, he then left with his army to supress a Yellow Turban attack in Yanzhou. He drove them all the way to Jibei. He took over as Governor of Yanzhou. In the Summer, Cao Cao led his army to defeat Yuan Shu in the region of Chen Liu, and Cao Cao defeated him at first and then out-manuevered him, forcing Yuan Shu to flee South. In the Autumn, attacked and won several battles against Tao Qian.
- In 194, his father was killed and he led another expedition against Tao Qian. He defeated Tao Qian's forces and was forced to return as several governors in Cao Cao's region had rebelled and allied with Lu Bu.
- In 195, he defeated Lu Bu and strengthened his grip on his region.
- In 196, he defeated another Yellow Turban army at Runan, defeated the army which escorted the Emperor to Luoyang and later defeated Yuan Shu.
- In 197, he campaigns against Wan, but is defeated, then he defeated Yuan Shu on two successive occasions.
- In 198 he defeated Zhang Xiu and Liu Biao's troops near Wan. He then went on to campaign against Lu Bu and defeated him.
- In 199, he dealt with a rebellion in Yanzhou
- In 200, he led his men against Liu Bei in Xuzhou and defeated them. He then campaigned against Yuan Shao in the North and defeated him numerous times.
- In 201, Cao Cao campaigned against Liu Bei in Runan, but Liu Bei fled as soon as he heard Cao Cao was leading the army.
- In 202, Cao Cao campaigned against Yuan Shao's sons, Yuan Tan and Yuan Shang and defeated them both.
- In 203, he campaigned intermittently against both Yuan Tan and Shang.
- In 204, he destroyed Yuan Shang and forced Yuan Tan to flee.
- In 205, he campaigned against the Wuhuan barbarians.
- In 206, he dealt with a rebellion from one of Yuan Shao's former officers and later campaigned against some pirates.
- In 207, he campaigned yet again against the Wuhuan.
- In 208, he attacked Liu Biao and his son surrendered. Afterwards he was defeated at Red Cliff.
- In 209 and 210, he did not campaign anywhere, dealing with defence and administrative matters.
- In 211, he campaigned West against Ma Chao and Han Sui, defeating them. He then defeated some bandits in the West and finally subdued Yang Qiu.
- In 212-214, Cao Cao campaigned against Sun Quan and defeated him.
- In 215, Cao Cao campaigned West against Zhang Lu and defeated him.
- In 216, Cao Cao doesn't undertake any military operations himself again.
- In 217, Cao Cao attacked Sun Quan and forced him to retreat.
- In 218, he did not take to the field again. By now, many of the operations were obviously delegated to the respective people with authority.
- In 219, he campaigned against Liu Bei to retake Hanzhong but was unable to defeat Liu Bei and retreated.
- In 220, Cao Cao died with 66 years of age.
As you can see, from the days of the Yellow Turban Rebellion, there was hardly a year where he didn't personally lead his armies somewhere, usually with a great deal of success. He was hardly as much of an administrator as he was of a General. He was widely known as a great General and tactician, and its known to have written a treatise of how to conduct war himself.
The fact that he unified most of the Empire with such a small powerbase (He had no previous powerbase), on such a small time-notice is awe-inspiring. Whenever he campaigned, he was
the General,
the leader, all strategies and ploys went through his hands, orders had to had his approval, so he is considered for all purposes and effects a General.