Definitely! That's what it's there for!
Generally speaking, when it comes to generic close combat weapons (chainswords, hekatarii blades, harlequin swords, glimmersteel blades, haemonculus tools) no one cares if you swap them around.
I've got wyches rocking the spear arms from the harpooners from the raider kit, and I've used wych arms all over the place (I love putting those trailing chain arms on hellions or reavers). The haemonculus gutting hook arms also look damn sweet on wych bodies.