What is Equilibrium to Shen?
So what does equilibrium involve? Being lawful neutral? Making sure for each serial killer you punish you also punish a Mr. Rogers?
It seems weird for a group to try and enforce equilibrium without any motivating emotions. If you don't have desires (emotions) or prejudices, why should you care what the balance is? To try and maintain an equilibrium, the group Shen leads must have be prejudiced towards and desire balance...which goes against their ideal of having neither of those aspects. Dispassionate judgment sounds good in principle, but in practice can lead to rather unbalanced outcomes.
Most stories I know of where there is a balance to be maintained have extremes to avoid. Heaven versus Hell is a common one. Too much Heaven- lack of free will. Too much Hell, chaos. But what extremes is Shen trying to push back against here? For every Zed he brings down, does he then go out and slay a Sona? Does he help Hecarim against Bilgewater if he thinks there is too much merry making going on there for balance?
If Shen tries to balance Good and Evil (as stated in Shen's spotlight), that doesn't work by definition. No one (except in Saturday morning cartoons) thinks what they do is evil. Everyone desires for more Good in the world and less Evil. What is Good and Evil is different to each agent of course. Shen would always be working for what he thinks as Good by maintaining equilibrium, as Good is equilibrium for him, which is not a balanced approach at all.