Now this is strange. Apparently, my scaled helmet(light armor smithing perk) is currently at 42 armor rating and it is rated Flawless. I have 80 smithing now and most of my other gears are exquisite/epic and my sword is Legendary(honed ancient nord GS). But why is my helmet flawless?
Also, comparing the scaled helmet with ebony helmet, the ebony helmet is rated exquisite but it has only 38 Armor rating while orcish has 32. This is so weird, how could a low leveled armor beat the ebony/orc ones?

Do you have perks in Heavy Armor smithing? Or in Light Armor, for that matter? If you take armor perks, the armor rating takes those into account when the item is being shown on the inventory screen. So for example if you have the perk that gives you an armor bonus for a matching set, and you're wearing a matching set of Leather Armor, but you look at a piece of Studded Leather or Elven armor, even though those are higher level armors, they could have a lower armor rating than your Leather Armor, due to the perks. Likewise if you compare light armor to heavy armor, but you only have perks in light armor, it's possible for the light armor rating to be higher than the heavy armor's rating, even if it wouldn't be if taken at base value.

As I understand it each Rank (Epic, Legendary, etc) has a range so one could be at the bottom end of one Rank and another could be at the top end of a lower Rank and be better. Also, for example, the Daedric base is better than Dragonplate base so that could factor into it and there could be similar relationships between other armor types.

Surely someone who understands it better than I will come along.

This. Also, I don't know if I'd call scaled armor low level. I recall scaled helmets being better headgear than most of what I found for a decent part of the game, though I never wear it because I think it looks stupid.

Yeah, it's above Elven Smithing and it's what some of the bosses in the forts wear so it's pretty good - especially at Legnedary.