#...imo

We can be fairly certain that Garak never took part in the torture of any Bajorans. Namely because the only allusions to him ever doing so were proven lies. (see: all of his calumny about “Elim” in “The Wire”)

For the most part, the Occupation was a military operation - and not an Obsidian Order one. 

Military Intelligence and Obsidian Order Intelligence are two completely different things, and OO operatives who were sent to observe Occupation happenings - Iliana Ghemor for example - were most likely sent there to ferret out disloyal Cardassians rather than Bajoran terrorists. 

The Obsidian Order serves mostly to micromanage conflict between the Cardassian Military and the civilian government - aka the Detapa Council. 

Odo has a line about it in “The Wire” that implies Cardassians themselves are more scared of the OO than anything else - this means that it deals with more issues of Cardassian nature, and you’d be hard-pressed to find an OO operative interrogating a Bajoran unless they had dirt on a very specific Cardassian official. 

Bottom line is that the Obsidian Order has no doubt killed FAR MORE Cardassians than it has any other species.

Cardassia is an Orwellian world. 

It depends on control of its citizens for survival, and it achieves that control by being constantly in a militaristic scare mindset. Anyone who goes against that is suspect and worthy of intensive mind flaying or death.

Cardassians are most afraid of other Cardassians.

When the civilian government is ineffective, and when the military cannot do its job, then the useless individuals must be eliminated.

This is what the Obsidian Order does.

The Obsidian Order does not bother with trifles like the Occupation. Rather, it just skims the surface and picks at the dregs left when it’s gone.

In fact, the Occupation was more than likely a happy accident due to the Military’s hubris. Events like that allow for morality to be tested and loyalties to be tried. Disloyal individuals like Tekeny Ghemor and Natima Lang float up to the surface and are therefore much easier to pick off.

I just wanted to make it clear that there is a division between military intelligence and the super-secret it’s-not-actually-supposed-to-exist off-the-record intelligence of the Obsidian Order.

Garak was involved with the smaller fraction of the Order that took out outside threats, but the vast majority of the OO is devoted to taking out threats to the Cardassian Union from the inside - which means torturing and killing other Cardassians.

There's a reason humans know about the Tal Shiar and not the Obsidian Order -it's because the OO is overwhelmingly busy with killing its own damn people and it only sends out like two or three operatives - "the sons of tain" - to do the work outside of the Union.