I decided to play a Dremora, which I achieved with a minimal mod of my own making. Since they can only wear Daedric armor, she spent her formative levels as a battlemage, using the flesh spells and the Mage Armor perk to achieve 350 defense (including Lord Stone bonus). She used a two-handed axe for close work, and destruction spells for ranged, and raised her smithing by upgrading her own weapon, equipping Lydia and a bit of grinding Dwarven bows and Gold rings.

Now she's dressed in Legendary Daedric armor (and wielding a Legendary Daedric Battle-axe). However, since she has no experience with Heavy Armor, that combo gives her half the defense she had naked. She can still boost it with magic, but the Mage Armor perk is negated, so she needs to level up the skill and get some HA perks quickly. What's a good method for playing catch-up? And what order is best for the perks - all the Juggernaut before the Well-fitted and Matching Set ones?

Don't forget the hidden 100 AR you get from real armor. If your AR is showing 175, that's actually equivalent to 275 with Mage armor, so add your ebony flesh and you will quickly exceed your old Mage armor protection with your Daedric Armor, notwithstanding that the displayed value may be less.

Your perk priority seems right to me.

Put on your stuff, wander out to the various ponds west of Whiterun and let the mud crabs chew on you - that'll get HA up.

Once you get bored of that, wander further north and let bears, ice wolves, or saber cats chew on you. You'll get HA boosted nicely, lickety split.

Mmmm... looks like Lydia gets left behind for a while. She'd intervene and kill all those critters before they do their work for me.

Right, good point - and no horse either.

You can also pay for training

That's a two-bladed sword, that cuts both ways. The problem is that you're not advancing your other fighting skills when you buy those five training sessions per level. So depending on what skill you train up, you may grow weaker against your enemies. It's the same problem you get when you gain a level by selling a lot of stuff, and advancing your speechcraft.

Generally I only buy training when my character needs to get "over the hump" to the next perk requirement. I can find better things to spend the money on (soul gems, spell tomes, potions, lockpicks, rare metal ingots, etc.)

But it's true, you can do it.

One mudcrab took her from level 32 to level 60 in Heacy Armor before boredom set in. Her earlier mage career gave her enough magicka regen to cast healing pretty well continuously, so she just stood and did that while the levels built up. Much cheaper than training, and no breaks. All perks assigned to Juggernaut, and now she has a respectable AR, and can get back to regular play.

Persistent little rascals, aren't they?