It's amazing how similar our ideas are Fault. Also, yes, the protagonists are Faradaians.
For Granardand, what I had in mind was a Stalin era-esque communist country ruled over by a dictator, with extremely heavy emphasis on defense. Your idea is somewhat like mine, but to go along with the defensive mindset, their hanzers are large, bulky and slow, but also humanoid. They have the largest and heaviest armor of any of the other country's hanzers, and all carry a large flat shield that resemble a scutum.
These shields would have bars or hooks that would allow them to connect their shields, then move in formation as a sort of slow moving unbreakable wall. Kind of like a phalanx, with hanzers standing behind pelting enemies with heavy weapons and artillery.
In essence, the Granardandian hanzer isn't made for combat, but instead to repel it, and never give an inch. They'd have a very dark motif, with their armor thick and worn. They have dark purple and white on their armor for their country insignia, a sword and shield (with the sword placed vertically in front of the shield). The armour heraldry idea is something I haven't thought of though, but I feel I'd have to ask what you mean. Also, I'd have to ask what you mean by the part of them resembling "human caricatures".
The Tenalian hanzers are indeed animalistic, but to go along with the arms race mindset, they would have animalistic features but also appear streamlined and new, as opposed to rough or jagged. For example, a character I haven't introduced yet that belongs to the Tenalian army would pilot a hanzer that has a spiked, serrated tail, resembling Ivy's whip from Soul Calibur. Others would have claws instead of hands, or double-jointed arms/legs and symmetrical bodies that would allow the pilot to, in the case of an attack from behind, simply re-orient themselves in the cockpit instead of turning the entire hanzer around. Others have goat legs legs and a more humanoid top half for jumping and traversing mountains. Somewhat like this:
So, in other words, the Tenalian army is varied, and uses it's variety to supplement it's tactics and be able to change up it's attacking strategy at a moments notice.
I like the color scheme you've chosen though. The Tenalian symbol is a diagnolly striped red, green, and white flag with a star in each corner.
The Faradaian army is, as already implied, almost completely humanoid. However, to stress the hierarchy of power as associated with it's monarchy, those with a high standing would have gradually more regal-looking hanzers, using more colors and having distinct patterns colored onto their armor.
I like the color scheme you've thought for this one as well. The Faradaian symbol would be a red diamond with a picture of the royal crown inside of it.