I've see endless complaint after complaint about Space Marine character Gabriel Angelus being too big. I strongly, strongly agree with this. It's interesting that nobody can seem to put their finger on exactly why he irritates everyone so badly. But I recognize the problem, and I have one novel solution to suggest.
The problem here from a professional game development standpoint is that his size puts him into a state of "Uncanny Valley". Uncanny Valley being the term that AAA game studio artists use to refer to fan repulsion and dislike of lifelike animated characters that creep us out by subtle differences from real pictures of humans. Gabe's art seems to creep everyone out by subtle differences not just to real humans on one side of the "Valley" at the 99 percentile, but also by being too different to the other Astartes on the on the 98th percentile side of the valley. So here we have the worst case possible, something that creeps us out while simultaneously breaking immersion due to inconsistency.
I do think his art needs to be changed before full launch. The simple answer is for him to simply be made 15% smaller. Then he simply appears to be a regular Space Marine in tactical terminator armor. Problem solved.
If you developers really want him to be bigger than everyone, that is cool. But you need to tweak the art a bit. Just add two smokestacks behind his shoulders to the model or replace part of his knees or legs with more obvious metallic bionics. This will make people think: "Oh, well he DID get chopped in half and rebuilt as a cyborg, I see those smokestacks/knee hydraulics, he must have been rebuilt as a custom lite-dreadnought thingie. Cool!".
I'll be frank, his proportions really are bizarre and I strongly urge that one of the two changes above be made before launch, otherwise he risks being the Jar Jar Binks of this sequel and we will hear endless, unnecessary jokes and memes about this.