Guild Wars 2

In the collection for each piece there is a pretty generic trophy….such as

dropped from bandits
dropped from nightmare court
dropped from sons of svanir
dropped from flame legion
dropped from inquest

are these just generic drops off the mobs, or are they in the mat bags that these types of enemies drop?

Generic basic drops straight from the mob, at least for the ones I got.

indeed, and they drop from any level mobs. doesnt have to be lvl 80. I killed a few nightmare court in caledon and got the drop off them

They are generic drops you can easily obtain by killing the corresponding enemies in the open-world. For example, flame legion in fireheart rise, nightmare court in caledon forest and so on.

As far as I recall, I got all of the pieces within a handful of kills.

and once you have the trophy, you can sell it correct?

What I have been told you need that yellow drop and the boss yellow drop to craft the item

its like all the items you craft to make armor parts usualy.

Jordo.5913:

and once you have the trophy, you can sell it correct?

If it says “only has value as part of a collection,” open that collection (often you can do so by right clicking the item) to verify it’s lit up for you. If so, yes, you can vendor it.