A Warlord is first and foremost, a Leader.
The concept of Leadership, for most, is an ambiguous, poorly understood thing - but the effects of Leadership are anything but ambiguous or intangible. Its presence is proven through success, its absence obvious in failure.
Leadership is a skill and an art. It's the ability to understand people - what makes them tick, what inspires and motivates them, and what their capabilities and potential are. It's also the ability to enable both individuals and groups to be better than they would by themselves - sometimes even knowing people better than they know themselves. They are facilitators and efficiency experts. They are coaches, mentors, and counselors.
And before anyone reading this gets their I-don't-like-to-be-told-what-to-do underwear in a twist, Leaders aren't necessarily one
In-Charge; and even the ones that are don't necessarily tell others what to do. In fact, good leaders rarely need to tell people what to do - or at least it never
feels like they are. (More about Warlords being
In-Charge here)
Mechanically, Leadership is best modeled by providing the group with a Synergistic effect - an efficiency/morale/inspiration bonus that the mere presence of a good leader generates. So far, with the Warlord we've been working on in the Warlording the Fighter thread, we're using a wild-card advantage application the group collectively chooses when to use.
Neither the Battle Master or the Valor Bard present a mechanic that effectively represent the advantage to the group of having a Leader. The Inspiring Leader Feat does not either. It only mirrors the Rally maneuver from the Battle Master.
After Leadership-generated Synergy, the next biggest thing a Leader provides is Inspiration...
A Warlord is a source of Inspiration and Perseverance
As said before, a Leader knows people. A Warlord takes that to the next step and becomes an
Expert at knowing
their people -
their Group. This ability to Inspire others presents itself in aiding others with tasks and rising above their temporary discomforts. They influence people to a state of mind-over-matter - allowing them to ignore, and even sometimes erase mental and physical conditions.
Mechanically, this means recovering Hit Points, erasing levels of exhaustion, and overcoming fear or other mental conditions - and yes, even rousing people from trauma induced unconsciousness.
Current inspirational hit point recovery mechanics in 5E only provide Temporary Hit Points. By the rules, Temporary Hit Points cannot restore a character at 0 HP - not to mention that the concept of inspirational recovery is to provide real, physical, Hit Points. (for more read
here,
here,
here, and
here)
And lastly...
A Warlord is a Master Tactician and Strategist
Warlords are not the best Fighter, same as a Coach is most often not one of the best players. What they are however, are chess players
par excellence. Fighters are masters of individual combat, Warlords are masters of group combat and strategic warfare - sometimes even Machiavellian manipulators. Their big-picture view of combat provides them the ability to expand the tactical options of their group.
Mechanically, this is modeled by the Warlord employing maneuvers that impart a tactical or strategic effect on a confrontation - and even extend their actions to another character to employ those tactical maneuvers instead.
I've seen it said this way: "A Warlord doesn't just hit an Orc; a Warlord hits the Orc with the Fighter."
For more specifics about what I've posted above, read
here and
here in the
Warlording the fighter thread.
In broad overview it was a tank, melee, bruiser, damage dealer, caster, healer and supporting class. For specific abilities you will have to wait for someone who remembers it all.
If one wishes to limit a broad overview to merely mechanics and mechanical roles... But even then, this overview isn't correct (and as you pointed out, also not comprehensive). Warlord's are not tanks, bruisers, or necessarily damage dealers. DPR (damage per round) is not a defining aspect of the Warlord. Caster also is not part of the Warlord - in fact it has absolutely nothing to do with a Warlord. Healer is a bit of a misconception also. Warlords don't "Heal", they generate Hit Point recovery through means other than Healing.
Also, arguably far more important than a list of mechanics and mechanical roles, are the narrative and roleplaying aspects you overlooked.
And Lastly, as concerns this:
...so many [Warlord] threads seem like just an argument rather than a discussion.
I believe this stems mostly from the desire by some to not just express their opinion as concerns a Warlord class, but to take it to the level that
it should not exist because they don't like it.
In response to that I'll quote one of ENWorld's more wiser members, @
Mouseferatu ... (far more wise than me, anyways...)
Quote link
here
Speaking as someone who
still doesn't have a strong preference as to whether the game includes a warlord or not...
The individual table is the pizza. The published game is the buffet. It's fine to leave peppers out of the pizza. It's less fine to demand the restaurant not include them at the buffet.