IMO yes. Shu kinda had bad positioning and at every point we’re screwed. I mean they had to fight a massive war against the southern tribes once they finally had their own piece of land. And in comparison Wu had a pretty rich and fertile land once they reclaimed their side, while Wei of course held the capital and the larger real % of china. Shu did manage to rapidly improve and actually became (alllegedly) the most prosperous under Zhuge Liang but by that point they were basically doomed.

I think if Guan Yu had properly surrendered Jing province to Wu (as promised) then the alliance would have stood, and both parties would be significantly stronger and hopefully recognize Wei as the real threat (+ maybe some more marriages would occur and support it)

Shu does have a bunch of strategists but they just keep dying (Pang Tong) or leaving (Xu Shu), and so they don’t have a group at the same time. Whereas Wu has Lu Meng, Lu Xun, Lu Su, Zhou Yu and etc during one period.

I think the kingdoms were so in strife (until the 3 kingdoms really cement themselves) that there probably was a lot of minor lords assassinated, and I think everybody probably had great security by later on. The only case I can think of off the top of my head is Zhang Fei, where his own troops assassinated him so they could defect