Um, guys Gogsun Zan & Lu Bu are known for betraying other people. Actually I believe Lu Bu stabbed Liu Bei squarely in the back. Cao Cao had no intention of keeping Liu Bei alive, Liu Zhang was incompetent & Liu Bei was doubtful of betraying Liu Zhang & Liu Biao. I mean I think it was wrong of Liu Bei to betray Liu Zhang, & i think him not really planning on giveing back Jing (Which was not Sun Quans, he never lifted a finger for it, if I remember correctly Sun Jian died attacking it, & it was Sun Ce's next target) was wrong, but Sun Quan did everything he could to stab Liu Bei in the back. Theres always Lady Sun, & while Liu Bei attacked Cao Cao Sun Quan interviened, & then there was also the aftermath of that in Yi Ling. I mean Sun Quan was way more treacherous, even historically.
BTW Guan Yu was a great general, but he was to arrogant to protect Jing all by himself, he needed someone good with political affairs to guide him.
I'm a lone wolf who got lost from the pack, and although he puts on a feirce face, he's still looking for his pack.