Should I define a part?

Good Day All,

I recently received a assembly with parts from a colleague. I opened most of the parts and I found that all of them are not defined with anything, I guess he just directly copied them all from autoCAD files and extrude them.

Is this okay? Should I define the sketching if I directly copy them from CAD drawings?

Thank you very much.

Keith

SolidworksParts And Features