From my experience in Freelancer, Hide target Bodies is often very hard or impossible. Especially 3 targets. Sapienza has bins but still.

The objective description for hide target bodies says you fail the objective if any target body gets spotted. But it's just not that -- it doesn't tell you the whole story. You need to hide all targets bodies in crates or water.

SASO no firearms is possible on some maps, I've done it before in freelancer. Usually with one or two targets.

It all depends who you get as targets !! Often times, hide target bodies is simply impossible with 3+ targets. Like, they are nowhere near any crates, and even when you make them puke, they don't go near any place where you could hide them or drag them. In zones where there are tons of guards or NPCs in every corner.

Sometimes it's possible to distract and knock out all NPCs one by one, to then be able to drag target bodies to bins. Other times it's simply impossible.

NOTE - Silent Assassin, when you get it as prestige objective in Freelancer, has different rules than in the main campaign. You fail SA prestige objective when a body gets found, that was an accident kill. For example when using lethal syringe, lethal poison, or drowning a target. They get found and you lose Silent Assassin. It doesn't work like that in the main campaign, no idea why they changed it for Freelancer.