Honestly, the texture of the Sentinel is amazing and I'm impressed at the details. I can see why Aeria games would pick it since it is very well designed is sending signals that this was not a sloppy Tera adjustment, but something that time and effort went into to deliver the best experience.
However even with a good stand alone design, you can end up with problems when you consider the whole concept. Mario works wonders in Super Mario, but he wouldn't quite fit in inside Alien vs Predator.
Scarlet Blade's attraction is that it plays on showing a lot of skin. Advertising itself as an adult title where you get to play as characters you won't find in many other titles. The sentinel design goes completely against the concept of this game, and that is why it gets so poor feedback. As I said, the texture itself is amazing, but you can't put that in Scarlet Blade. Perhaps you can put it in Star Craft, or in Star Wars, but not here.
The most important part here is that you should be able to place her in just her underwear, and still get the feeling she resembles the other characters in underwear. When it feels like it is a completely different game, there is something wrong.
I completely understand you worry about Sentinels in their "naked mode", but you could as well just have gone with bandage wrapping around her chest to claim she is also size D but she thinks the breasts are in her way when fighting.
tl;dr Tell the developers I love their Sentinel design, but this game needs Sentinels showing more skin or it will be censor talk every day on the forums for the following 2 years.