Aigis story maps are very uneven. The difficulty can suddenly ramp up significantly from one to the next. Most times, there is no choice but to just keep leveling the core units and add affections until they can overcome said map. Occasionally, you can try to circumvent that by using rogues for dodges or assassinations when rushed with an early powerful unit.
In Armor of the Dead, the rush is early and with mostly goblins and two hard hitting armor enemies. A weak heavy armor will get completely destroyed if you attempt to block them both together, as each will deliver almost 500-600 damage per hit to a 0 defense unit. So unless the HA is at least 300 defense or higher there is just no chance to tank that. The best initial deployment for this map is probably a Misha/Elaine/Kerri at the crossroad to farm some UP, Katie 2 spots below, then a rogue (like Cypria) at the spot below valkyrie. Have a healer out after that when possible to cover all 3. Black armor will be on the valkyrie unit first, and depend on when the healer is out, can only take 1 or 2 black armor hits. Withdraw valkyrie before she dies, and let the rogue tank the black armor and activate assassinate skill. Pray for RNG so that the black armor dies before the rogue does. Deploy prince, 2nd healer or mage in the meantime when able. The rest is significantly easier after the initial onslaught is dealt with and the healers, mages and tanks are deployed.
