Here are my guide to the main players.
Cao Cao – Julius Caesar
They both were great generals. Cao Cao conquered Northern China while Caesar conquered Gaul and defeat Pompey.
They both were learned men. Cao Cao and his sons’ were famous poets. His in-game trailer song was based on one of his poetry. Here’s another war poem by Cao Cao. Caesar’s commentaries were the standard books for teaching Latin.
They both clearly coveted power but tried to work within the existing system to gain legitimacy. Cao Cao appointed himself Chancellor and striped the Emperor of any power. Caesar appointed himself Dictator and striped the Senate of any power.
They both had an old friend who became their greatest enemy (Pompey and Yuan Shao), defeated them while greatly outnumbered (Pharsalus and Guandu) and cried when their old friend died.
Their successor created a new power structure. Cao Pi established the Wei Dynasty. Augustus became the first Roman “Emperor” in all but name.
Liu Bei - Aragorn
They both are blue blooded. Liu Bei is a descendant of Emperor Jing, an emperor of the older, more virtuous Han Dynasty. Aragorn is a descendant of Isildur, a king of the older, more pure Gondor.
They both wants to restore their kingdom to their rightful place. Liu Bei wants to restore the Han Dynasty. Aragorn wants to restore Gondor.
They both have a right to the throne, due to their noble lineage- even if they are both in humble circumstances at the beginning.
They both crowned themselves Emperor/King although Liu Bei failed in his goal to unite the Empire.
They both have two close companions. One is noble fierce warrior. The other is a bearded comic relief warrior.
Sun Clan – The Starks
The Sun Clan ruled in the south east while the Starks rule in the North. Both lands are vast, under populated and relatively improvised. The Sun Clan claim to be a descendant of Sun Tzu while the Starks are the descendant of the First Men. The Sun Clan are associated with the tiger while the Starks are associated with direwolf.
Sun Jian - Ned Stark
Both are arguably fair leaders and great generals. Sun Jian lead the vangard against Dong Zhou. Defeated Dong Zhou's army in Yangren and killed the enemy commander Hua Xiong. Later he was the first to enter Luoyang (capital of Han Dynasty). He entered Luoyang to discover that the city has already been sacked and burned by Dong Zhou. Ned Stark lead the vangard against Targaryen. Defeated Targaryen 's army in Trident and killed the enemy commander Prince Rhaegar. Later he was the first to enter King's Landing. He entered King's Landing to discover that the city has already been sacked and burned by the Lannisters.
Both are loyal to the current power structure. Sun Jian is one of the last Han loyalist. Ned Stark one of the nobles who is really loyal to his King Robert Baratheon.
Both meet unfortunate ends at the beginning of the story.
Sun Ce - Robb Stark
Both were very young when their father’s death. Sun Ce was 16 and Robb Stark was 15.
Both are arguably even better generals than their father. Sun Ce conquered the south east of China and was nicked named “The Little Conqueror”. Robb Stark defeat the Lannisters multiple times and was nickname “The Young Wolf”.
Both did not submit to the current power structure. Sun Ce never mentioned upholding the Han Dynasty and was more focused on conquering his own territory. Robb Stark was named "King of the North" and refused to submit to King's Landing.
Both did not make political good decisions and was killed by assassins.