In the historical era as turbulent as the Three Kingdoms, alongside the battles of wit, the competitions among the top generals were always captivating. The victories of these generals in individual combat also significantly boosted the morale of their respective armies before battles.
Among the renowned generals of the Three Kingdoms, we cannot overlook Guan Yu, Zhang Fei, and Zhao Yun. In terms of martial prowess, all three are formidable opponents that command respect. However, without direct combat, determining the victor is challenging, as all three are part of Liu Bei's 'Five Tiger Generals' and share a strong fraternal bond.
So, when considering overall capability, how can we determine who is stronger?

The answer to this comparison conundrum can be deciphered through analyzing the common adversary of Guan Yu, Zhang Fei, and Zhao Yun. That adversary is Cao Cao.
The answer to this comparison conundrum can be deciphered through analyzing the common adversary of Guan Yu, Zhang Fei, and Zhao Yun. That adversary is Cao Cao.
Tao Thao's Assessment of Guan Yu
Following Liu Bei from the early days of his career, Guan Yu quickly rose to fame in the Three Kingdoms period. Tao Thao also swiftly took notice and admired Guan Yu.
In 190, during the coalition of 18 lords against Dong Zhuo, the cavalry commander Hua Xiong repeatedly struck down many generals. At that time, Yuan Shao lamented: 'If only Nhan Luong and Van Xu were here. With one of them present, there would be no need to fear Hua Xiong.'
Subsequently, Guan Yu stepped forward and quickly displayed his prowess by killing Hua Xiong, astonishing the lords. This feat of Guan Yu immediately left a deep impression on Tao Thao.

Tao Thao showed special concern for Guan Yu, even once pleading with Tao Thao to spare a man for Guan Yu's sake. In 198, after defeating and killing Lu Bu at Xia Pi, Tao Thao captured Zhang Liao. Just as Tao Thao was about to order Zhang Liao's execution, Guan Yu spoke up in plea.
This surprised many, as the famously proud Guan Yu unexpectedly pleaded with Tao Thao to spare Zhang Liao's life.
Out of admiration for Guan Yu, Cao Cao decided to spare Zhang Liao's life. This valiant general submitted to Cao Cao and later achieved many distinguished accomplishments for the Cao Wei.
By 200 AD, Cao Cao led his mighty army to advance on Xu Province, causing Liu Bei's forces to crumble in defeat. At that time, Liu Bei fled to Ha Bac seeking refuge with Yuan Shao, while Zhang Fei escaped to Southern Nam Viet. Meanwhile, Guan Yu was compelled to surrender to Cao Cao, accompanying him to Hua Xiong's camp to safeguard Liu Bei's kin.
This renowned commander even dared to set conditions with Cao Cao, known as the 'Three Pledges Agreement', emphasizing loyalty to Han, not to Cao, and promising to seek out Liu Bei's whereabouts if known. Despite these irrational terms, Cao Cao not only accepted them but also sought to win Guan Yu's favor by all means necessary.
Accordingly, Cao Cao bestowed upon Guan Yu beautiful women, fine wine, gold and silver... even Xích Thố, the renowned steed once ridden by Lu Bu. Furthermore, he petitioned Emperor Xian of Han to grant Guan Yu the title of Marquis of Han.
During his temporary allegiance to Cao Cao, Guan Yu achieved numerous distinguished feats, such as slaying Nhan Luong and Van Xu, Viên Thiệu's top generals, in the Battle of Bach Ma in 200. Even the mighty general Tu Hoang could only hold out for 20 bouts in single combat against Nhan Luong. Therefore, Guan Yu's ability to easily slay Nhan Luong amidst enemy lines astonished everyone. This accomplishment once again showcased Guan Yu's exceptional combat prowess.
Naturally, the consecutive killings of Viên Thiệu's two beloved generals only deepened Cao Cao's affection and desire to subdue Guan Yu.
Unfortunately, Guan Yu's unwavering loyalty to Liu Bei led him to reject all the offerings bestowed by Cao Cao. Upon hearing that Liu Bei was with Yuan Shao, Guan Yu immediately set out to find him. In order to keep Guan Yu, Liu Bei did not grant him passage through the checkpoints. Guan Yu managed to pass through five checkpoints, defeating six of Cao Cao's generals to clear his path.
Seeing this, Cao Cao still sent a decree to release Guan Yu. This alone indicates how much Cao Cao admired Guan Yu's talents and character.
Besides being an exceptional warrior, Guan Yu was also a skilled tactician. This was evidenced when Guan Yu defeated seven Wei armies at Fan Castle in 219, capitalizing on the floods.
After defeating the seven Wei armies and slaying the Wei general, Pang De, Guan Yu planned to exploit his victory, advancing towards the capital to capture Cao Cao.
Upon hearing of Guan Yu's resounding victory, Cao Cao was greatly concerned, even considering relocating the capital and escorting Emperor Xian of Han out of Hua Xiong.
Aware of Guan Yu's martial prowess through his illustrious deeds in the Three Kingdoms era, but it was Guan Yu's military prowess in current campaigns that truly struck fear into Cao Cao's heart, even prompting him to consider relocating the capital. Therefore, it is clear that to Cao Cao, Guan Yu was the strongest military strategist.

In the year 208, during the Battle of Truong Ban, Liu Bei suffered a heavy defeat and had to retreat. Cao Cao led his army in pursuit and caught up with Liu Bei at Duong Duong - Truong Ban.
At that time, Zhang Fei was tasked with blocking the rear to cover Liu Bei's retreat. Leading 20 cavalry soldiers behind, Zhang Fei chose the Truong Ban bridge to observe the enemy's situation.
Standing alone on the bridge with his horse, Zhang Fei shouted loudly: 'I am Zhang Yide, from the land of Yan. Who dares to face me in a life-and-death battle?'
Zhang Fei's thunderous roar was like thunder, causing Cao Cao's army to tremble with fear. According to the Romance of the Three Kingdoms, Zhang Fei continued to shout loudly, unexpectedly terrifying Hua Xiong, a general next to Cao Cao. Seeing this, the commanders of Cao's army dared not attack. At this moment, Cao Cao recalled Guan Yu's words about Zhang Fei's strength and feared being ambushed, so he decided to retreat.
From the above analysis, it can be seen that Cao Cao was wary of Zhang Fei's strength.
Cao Cao praised Zhao Yun

Tao Thao highly values the loyalty, courage, and dedication to his lord exhibited by Zhao Yun. In the Battle of Truong Ban in 208, Zhao Yun's lone charge to rescue Ah Dou (Liu Bei's son) from Cao Cao's encirclement left a strong impression on Tao Thao. Impressed by Zhao Yun's combat prowess, Tao Thao praised, 'Truly a tiger general'.
Tao Thao ordered his soldiers not to shoot arrows and to capture Zhao Yun alive, intending to recruit this talented general. This gesture expresses Tao Thao's appreciation and recognition of Zhao Yun's abilities.
To Tao Thao, Zhao Yun is a rare talent whom he desires to recruit. Throughout his life, Tao Thao has encountered many heroic figures such as Lao Bo, Guan Yu, Zhang Fei, and many other valiant generals. Therefore, to Tao Thao, Zhao Yun is an admirable talent.
So, according to Tao Thao, who is the most well-rounded powerhouse?

Based on the analysis above, it can be seen that Tao Thao admires Guan Yu for both martial prowess and military strategy. The ruler of Wei regards Zhang Fei highly for his martial arts prowess and praises Zhao Yun for his rare martial skills.
Therefore, according to Tao Thao, Guan Yu is the most powerful and well-rounded general, followed by Zhang Fei and finally Zhao Yun.
References for this article: Sohu, Baidu, Sogou