I actually did this a long time ago in my mod:
I even requested a custom icon by the creator of the CoH2 Avatars and Icons guide on Steam, so props to him.
Anyhow, my reason for this is that I'm really... "tired" of the current Grenadier models and their weird looking camo, which doesn't fit in with the rest of the Army in my opinion, plus the Arty officer's retinue are using the same weapon crew models and I think they look better and fit in more than the all camo-ed Gren models that are currently in use. At least the Panzergrenadiers have the same pants as the rest of the units.
Well, that's about it, thanks for reading in advance and have a nice day.