The rapid surrender of Liu Yu and Cai Mao was indispensable both because of their serious internal divisions and the success of Xun Yu's "indirect line" strategy. With these two factors, even if Liu Biao is there, I am afraid that the situation may not change much.
Liu Chun's internal situation: few soldiers and split First, correct the 250,000 troops in the title. The strength of Liu Biao's group at that time should be about 100,000. When Liu Chun surrendered to Cao Cao, he brought more than 70,000 surrenders. Liu Bei and Liu Qi, who did not surrender, each had more than 10,000 troops, and if you count the troops (about a few thousand) lost by Liu Bei in the Battle of Changbanpo, the total is more than 100,000.
100,000 troops, if the strength of the troops to defend, it is not impossible to fight. However, at this time, the LiuBiao Group had already split. (It was split before Liu Biao's death)
"Going up to the house and drawing a ladder" shows that when Liu Biao was there, the two princes had each pulled foreign aid and split the pit. At that time, the powerful factions in Liu Biao's group supported Liu Biao's two sons. Liu Bei supported Liu Qi; Cai, Ku and other local scholars supported Liu Qi.
Although from the perspective of the strength of the troops he had, Liu Chun should have the advantage, it did not mean that Liu Chun's military strength was stronger. Jiangxia, where Liu Qi was located, was the front line for Liu Biao's defense against Sun Quan at that time, and Fancheng, where Liu Bei was located, was the front line against Cao Cao. There is reason to believe that the forces supporting Liu Qi are not weaker in combat strength than Liu Qi. In fact, when Liu Qi learned of Liu Qi's succession, he had planned to take revenge on Liu Chun in the name of funeral; Zhuge Liang, when he learned of Liu Chun's surrender, also suggested that Liu Bei attack Xiangyang.
In fact, after Liu Biao's death, Liu Chun himself hoped to fight. When Fu Xun persuaded Liu Chun, he took a whole bunch of high-sounding principles such as local confrontation with the central government, and the key point was: If Liu Bei could defeat Cao Cao, Liu Bei would turn around and kill you; if Liu Bei couldn't defeat Cao Cao, Cao Cao would kill you.
It can be seen that Liu Chun's final surrender was not only fear of Cao Cao, but also the fear of "his own people" was the key to finally prompting him to make up his mind to surrender.
Jingzhou, the prey of the group, is the prey of the group at this time.
Sun Quan: Plans to occupy Jingzhou before Cao Cao
As early as the winter of 200, when Sun Quan had just ascended the throne, Lu Su suggested that Sun Quan keep Jiangdong and go to Jingzhou, but at that time Sun Quan's position was unstable and he did not act.
In 208, Gan Ning again wanted to destroy Jingzhou before Cao Cao, and this time, Sun Quan adopted it. In the same year, the Jingzhou army was defeated and Huang Zu was beheaded.
Liu Bei:
The Longzhong Pair has incorporated the capture of Jingzhou into Liu Bei's strategic steps. Liu Bei was making friends with the Jingzhou shi clan and actively expanding his influence in Jingzhou, and was suspected of planning a "peaceful evolution" in Jingzhou.
The saying that Cai Mao and other scholars had long wanted to threaten Liu Xuan to surrender was debatable the more popular saying at present was that Cai Mao and other scholars had long wanted to surrender to Cao Cao.
In fact, it was indeed relatively easy for the warrior clique to abandon resistance and obey the strong. After all, the harm of war to vested interests is something they do not want.
If Cao Cao's strategy is not proper, the "surrender faction" in Yingzhou may also be like the "main descending faction" in Eastern Wu, insisting on insisting on taking a look first. However, looking at the various warlords during the Three Kingdoms period at the end of the Han Dynasty. It was only in the final stages of the war that they began to organize the "great cause of surrender." Like the Liu Chun clique, very few people surrendered "without fighting."
In the case of Cai Mao, who was in Jingzhou, was a powerful figure under Emperor Tu and held heavy troops, which was much more advantageous than later being a higher-ranking virtual warrior clan under Cao Cao.
Therefore, if they want to give up resistance quickly, they also need to adopt the right strategy. Otherwise, these Jingzhou warriors, like the warriors who instigated Sun Quan to surrender before the Battle of Chibi, would continue to support the division.
Being a warrior emperor with heavy troops and a mighty style is exactly the reason why all the warriors in history who support the division support the division. No one wants to give up until the last resort. Cao Cao was able to quickly "force a landing" of Liu Zhen and Cai Mao, thanks to his correct strategy.
Cao Cao's indirect route strategy was appropriate
What prompted Liu Chun to surrender quickly was Cao Cao's correct strategy.
At that time, although Cao Cao's strength was strong, Jingzhou was after all a land where the river network was crisscrossed, and it was not necessary for Cao Cao to move with force. Later, whether it was Guan Yu or Sun Quan, the strength of the configuration in the Jingzhou area was not as good as that of the Liu Biao Group. However, Cao Wei's offensive in the region was ineffective, which showed that at this time, Liu Biaojun was by no means unable to fight because of the gap in strength.
At this time, Xun Yu's suggestion played a huge role.
Xun Yu suggested: "Huaxia has been pacified, and the southern soil is in difficulty" to act with great fanfare between Wan and Ye, creating the illusion that it is still a local campaign. However, the main force entered Jingzhou "in the middle of the road" to directly deter the ruling group of "Southern Tu". This suggestion was adopted by Cao Cao.
This is the strategy of a strategic raid.
If Cao Cao's army took a direct route of advance, Liu Biao's army was likely to resist step by step, gaining sufficient time to mobilize. And the factions within the group may also "rush to each other" and temporarily hug together.
However, the "middle road" entered Jingzhou, avoided entanglement in the enemy's predetermined battlefield with its surprise attack effect, and directly burned the war to the area near the vested interests of the Jingzhou interest group, deterred the capitulating forces within the Liu Biao group, and was likely to divide and disintegrate the resistance will of the Liu Biao (Liu Chun) group.
The flames of war had already burned into the area near where the interests of the warrior clans were located, and the Cai family and other clans who were good at building houses and fields, even if Liu Biao was still alive, how could they go to war with Cao Cao under such circumstances?
At the beginning of World War II, the German army also took advantage of the inertial thinking of Britain and France to create the illusion of continuing to implement the "Schlieffen Plan", but the elite armor took the Ardennes Forest and entered France, directly cutting off the British and French allies, causing the psychological collapse of the French "capitulationists" and forcing them to land in France. Unfortunately, this seems to be the last time Xun Yu gave Cao Cao a "strange strategy". Guo Jia had gone, Xun Yu did not say a word, Cao Cao lost his wisdom, and finally Chibi was defeated, losing the opportunity to unify the world, which was a pity.
Therefore, the reason why Liu Zhen and Cai Mao, who still had combat strength, surrendered quickly was because of their own chaotic situation and because of Cao Cao's correct strategy. Both are indispensable.