Based on the brainstorming I did on heralds for the player guide discussion yesterday and today, I decided it's worth putting out a more fleshed-out proposal. The idea is to address the largest issues with heralds while staying as close to the current mechanics as possible. I'll try to keep it in an outline form for readability, since it may end up longish.
Concept: Eliminate the mellee assist role of heralds. A herald is a dude carrying a flag, he's probably not able to engage in hand-to-hand combat effectively. Instead, make heralds "walking buff sticks", giving them one fellowship buff (instead of aura), and several Captain-only buffs. Heralds may still take damage and die, but the Captain should have some tools to protect them (more on this later).
General Behavior: Heralds have no attacks of any sort (including auto-attacks). They can still B/P/E if attacked, and take damage normally, but will not assist or otherwise engage in combat.
Fellowship Buff ("Raise Banner"): Different for each type of herald, long range, perhaps a 30s buff on 60s cooldown. May simply be equivalent to current auras, but other options that came to mind were:
War: +crit rating, +crit defense
Hope: +(substantial?) ICPR, +tactical mitigation
Victory: +(substantial?) ICMR, +physical mitigation
Captain Buffs: General philosophy is to use a "lend" mechanic, where the herald provides a portion of his own level of respectable stats to the Captain.
Lend Courage: Heal Captain for X morale, Cost: X morale
Lend Power: Heal Captain for X power, Cost: X power
Lend Prowess: Buff captain with Y% of Herald physical mastery
Lend Wisdom: Buff captain with Y% of Herald tactical mastery
The reason to structure buffs this way is that they actually make it beneficial for the herald to be your X-brother, and makes use of offensive buffs/tactics that would otherwise have been lost on a herald that has no mellee attacks.
Trait Tree Changes: Heightened Allies in the red line will increase the percentage in Lend Prowess/Lend Wisdom.
New Herald Skill: Withdraw from Battle. Works the same way as the Captain, intended to make sure Herald can buff more reliably.
New Captain Skill: Valiant Rescue. Captain copies herald's threat (+20%) for each mob if this number is higher than the captain's threat. Idea is to keep herald unengaged while not losing aggro in the process.
This is decidedly rough around the edges, but I thought I'd throw it out there since the discussion got going a little bit already. Thoughts?