How could Liu Bei, who used to had no land of his own, could managed?
Historically: Liu Bei was benevolent in comparison to his other warlords and especially his rivals. Cao Cao frequently committed massacres and plunder while Sun Quan frequently raided Jiangxia and massacred a few cities here and there. Liu Bei has zero recorded massacres and only four recorded plunders. Twice as Yuan Shao surbodinate, once under Liu Biao direct control and the final one, he did it to reward his troops and he did not hurt the common folk. Liu Bei was an able commander. Not the best and not one of the better ones but he was above average. He defeated Yellow turbans, stalemate against Yuan Tan for a few months, stalemate against a numerically superior warlord in Yuan Shu, caused trouble in Runan twice unmolested for some time, raided Wancheng unopposed, ambushed Xiahou Dun, conquered BaShu while being isolated in the first half of his Sichuan campaign and finally killed Xiahou Yuan. Whenever he is given proper resources, he can pull off a few victories here and there. Liu Bei was charismatic as noted by the histories. Even though he constantly fled around, by the time he declared himself Emperor, most of his surbodinates were all from different parts of China. From part ethnic minorities like Ma Chao to northerners like Zhang Fei and the Southerners he inherited from Liu Biao and of course Liu Zhang. Liu Bei was able to inspire capable loyalty. Guys like Guan Yu, Zhang Fei and Zhao Yun all followed Liu Bei when he was a common surbodinate under Gongsun Zan to him being King of Hanzhong even after his many losses. Liu Bei had unmatched cunning and was quite the intelligent person to trick Cao Cao and Sun Quan while able to also cleanly backstab Liu Zhang. Who else can claim that they are capable enough to do all these while still being Emperor in the end. Liu Bei was respected as a "hero" directly by Cao Cao, Cheng Yu and Zhou Yu. That surely counts for something. Lastly, Cao Cao had strong connections to the gentries when he first started out. Sun Quan inherited JiangDong from his brother. Meanwhile, Liu Bei grew up a peasent to eventually become an Emperor of 1/4 of China. Liu Bei had heroic talent and as Chen Shou put it :" the charisma of GaoZu".