Halo 4-5 Armor vs Halo 3 and Reach Armor?

Is it just me, or does the armor for the Gen II armor look actually less protective than the Gen II armor.

Gen II seems to have removed several pieces of armor plating, around the middle of the torso where your gut is located, the crotch, upper arms, and for some reason the area between your heel and the front of your foot. The armor looks rather loose as well, like it could slip or fall off. It does however look more flexable.

Meanwhile Gen I has more protection in these places compared to is successor. With armor covering most of the vital places, the only thing i noticed is that the armor in Reach made it appear that it would be difficult to look down. While the spartan looked more intimidating, arm movement looked restricted, though it could just be the game model as well.