Suggest you go read about the more serious but boring books on sexpert finding in Sanguo like the economy, the law, the livelihood of peasants etc.
Then you will know that the so-called relaxed rules by previous incumbent of Shu ish all bull$hit. Like it ish also very relax in big loan sharks law that allow lich\elite to loan $$$ to peasant kia with high interest, then when peasant kia cannot pay, they will take away the land of the peasant kia. If still cannot pay, take take away peasant kia daughter and son to work as maid and $laves, if still cannot pay, the peasant kia themselves become $lave. Then ish generation of $lavery for the family after that.
Another way of those shu elite forcing peasants into $lavery ish entice them to sign up lease for land. the elite will lease them land but every harvest must give elite some portion as payment if can't pay the debt will add up with high interests. If harvest good still okay peasants can tahan and pay, but if poor harvest, many will tio pwn if they can't pay the elite enough. Then end up sell chewren into $lavery and eventually themselves.
And think you confuse ZGL era with Jiang Wei\Liu Chang era.
When ZGL up lorry, Shu ish still at it's prime. People nowadays blindly kpkb about his failed campaign against the North but in actual fact ZGL had been so over careful (that why also seldom yield result in war and war need risk) that his failed campaigns didn't wear out the country at all.
It was after Jiang Wei take over and try a few risky campaign that resulted in huge lost that eventually worn out Shu treasury and manpower. And it didn't help that Liu Chang ish not a capable nor charismatic ruler and after ZGL dead he also like to listen to Gold 90.5FM only..