Think about it

The Brute is wearing what I would have called "Plate armour" 
Very rigid-looking, bulky and almost entirely full body.

The Papal guard, however, only seems to have plate pauldrons, gauntlets and boots, and a helmet. He also appears to be wearing something under his chest insignia, but I can't quite see what.

And the Captain is wearing a Chestplate, pauldrons, gauntlets and boots, and a helmet. He's very well protected, but it's not all bulky and stiff-looking. I doubt he could duck and weave as easily as someone in lighter armours, but it certainly doesn't seem very obstructive.