Dark age aggression isn't too viable for both HRE and Order of the Dragon. HRE gets more movement speed, but Order of the Dragon gets stronger units even with a delay. So defensively, Order of the Dragon is stronger; aggressively, HRE is a bit stronger. They cancel each other out.

Gilded Men-at-Arms have a lot more stats than normal Men-at-Arms, but normal Men-at-Arms for HRE have a lot more movement speed. So if the Gilded Men-at-Arms walk across the map and get caught by two or three Men-at-Arms, they can easily be surrounded. With the option of healing with the Prelate, you can almost kite them, do damage, run the weakened Men-at-Arms away, heal them back up, and go for the engagement again.

Order of the Dragon gets a baseline +28% gather rate on villagers; HRE needs to actively inspire for +35%.

Gilded crossbowmen are akin to hand cannons in Castle Age against armored units, with a lot of DPS and additional range.

Spearmen for the Order of the Dragon are excellent, even against men-at-arms. They've got a great base damage, high health, and they're not taking any bonus damage from the crossbows, as well. So, they're really good meat shields.