smbakeresq
Explorer
Anyone who played a video game can tell you that the holy trinity is tank, healer, and damage. If the Cleric is literally the only actually effective healer in the game, it is an absolutely essential class for every single party. The whole point of the Warlord was to make the Cleric non-essential, or in 5E, allow Clerics to spec as anything but a healer without screwing over the party.
The tank, or defender, was a concept built around damage prevention and target redirections. If the Warlord did that, it would just be identical to the fighter. There are also dozens of situations, situations which are encountered frequently, in which damage absolutely cannot be avoided and no amount of buffing damage will make up for or prevent those situations.
Also, any number of monster abilities can render a PC inoperative in a single action and if there is only one class in the game that can reverse or prevent that-- then the party absolutely MUST have that class and any other class invented that is supposed to be an alternative but has absolutely no way of reversing these effects or restoring HP may as well not exist. It isn't an alternative at all-- it is simply and flatly a trap for inexperienced players who don't know better.
So whether you like it or not, whatever the Warlord does, it must be able to be a support class option that can do all of the essential support options that a Cleric or Bard can do. Of course, it doesn't need to have the turn undead ability or offensive spell-casting abilities of the cleric nor the illusion magic or superior skills of the Bard.
You don't need to play a video game for that, its been around in D&D way before video games were a thing. Video games took the idea from D&D and its ilk.
Otherwise you are along the right path. It should never be a replacement for a dedicated cleric. Bards are the 5th wheel type class that can cover for another class partially, Warlords should be along that rail but with a more (much more) martial bent.