Mostly, I was concerned at how having appropriate scales would make lighting (from HDRI, sun, etc) would make it more realistic. But having said this, I think doing a one-off shot of the Beetle Bot wouldn't be much of a concern?
It's mostly considered a "best practice" approach to model to scale, not necessarily a obligatory necessity. Not having things to scale does impact the lighting or any simulation you want to make and other things as well. Specially lighting becomes sort of a pain when you're trying to light a small bug and you realize it's the size of a building and now your light power goes into the 10,000 and 100,000 and you feel it's just ridiculous. So it's always better to model to scale.