I know I'm getting into a hornet's nest with this one and I agree the punishments are too light for what they did and intended to do, but we're forgetting several circumstances surrounding it:
- The battle was relatively bloodless. Sure, there were a lot of wounded, but nobody actually died. The loss on both army and Krumfal was negligible, if that. Were the fighting become a bloodbath, with hundreds of dead and wounded on each side you can bet those three wouldn't be breathing right now.
- Their objective was actually "just" the murder of a landlord, the princess wouldn't enter the equation (but she would have intervened for sure, and gotten hurt or killed most likely). While serious, that isn't that serious of a crime. In older times, it happened with alarming frequency. If anything, the bigger problem is that the state's armed forces were lied into being involved, and by one of their own no less.
- As for said landlord, the MC, he told them to show mercy. You can say "he's the same who destroyed a castle and everyone inside before" and you're right, but he felt pretty regretful about it afterwards and probably doesn't want to dirty his hands again.
So in this regard, weaker punishments would be more understandable. However, if you look closely into the punishments themselves they're not as merciful as seems, in a
poetic kind of justice:
- The military noble was forced to retire. Well, for starters military head honchos in older times (pre-WW1) tended to place A LOT of importance on gaining honour and glory in war and they essentially took that from him. Not only that, but he's implied to have been the equivalent of dishonourably discharged. That means every single achievement or shred of honour or glory he earned in his entire career is ashes, gone and never to be recovered again. Sure, he didn't look the type to care about those things, but that he became essentially a dead man walking after the "retirement" meant that he cared a bit about them, at least.
- As for the other two, not only is implied that they lost their noble position, as they have to seek successors for them (in my opinion, maybe the MC ends up with a greater peerage in the near future); but that they're essentially condemned to forced labor. Sure, in an office instead of a mine, but still forced labor. For noble twits like them who apparently never worked a day in their life and took their privileges for granted, such fate must be worse than hell. And who knows if they're being paid at all, but I don't think so.
So yeah, while I understand their punishments are way too lightly, taking how the issue actually turned out and the actual punishments I think they're not
that bad. Still weak, though; those punishments in actual captivity would have been better.