Fair points but the size differential between Chiesa and Luque will still likely be larger than the size difference between Luque and RDA. I don't think Luque is a tiny WW, but he looks average sized at best and maybe a bit below average in terms of size.
Meaning that although Luque is bigger than RDA, he's still probably closer to RDA's size than he is to Chiesa's. That's just me eyeballing it though, I don't want to make it sound like there some sort of basis for this view other than my own eyes.
And to be clear, "skinny and weak" Magny has outgrappled some pretty big WW's (Gastelum when he was at 170 for example). Magny is wiry, but calling him "weak" seems off.
The weigh in will be interesting. I could be wrong, but I still think we will see a somewhat noticeable size difference between Chiesa and Luque. Chiesa might be the biggest WW on the roster.