I personally love the way the marines look in Halo Wars 2. The 343 style of helmet fits in pretty well with the armor, which reminds me a lot of the original marines from Halo: CE.
The 343 style of armor alone is crap. In Halo Wars 2 we see a combination of bungie and 343 and it looks good. My main complaint was that the Helmets didn’t have enough of an overhanging visor but that’s been fixed.
I prefer the halo 2A marines (which are the marines in the cutscenes), but I’m fine with the gameplay ones.