Even after 20 years with
GW models, I still convert my models all the time, even from the new ranges. I have a skirmish collection of a dozen Stormcast, who all have headswaps with bareheaded Space Marine heads, several of which had to have the ear-comms removed and a new ear sculpted in so the head would have no tech-bitz.
Lord Relictor with head and staff swap:
I just recently made this custom (albino to add some character) Orc Shaman from a Savage Orc standard bearer I bought as a single at GenCon, simply by cutting down/resculpting the standard: