I did address the level dipping in my hypothetical proposal.
High at-will damage can't be broken if it's exactly the same as another class. You simply have to balance it like you would balance a rogue or warlock. You treat it like a damage class, not a support class.
Its not the same as another class though its the same as whatever class you need at the time and even a sorcerer for example built around spamming haste can't do what you want at level 10 using daily spell slots.
You post about the action granting did not address level dipping at all, and your action granting is actually the old 3.0 haste spell at will and that spell was broken as hell and was nerfed in 3.5. Its still broken in 5E.
The way 4E enabled at will attack granting was by defining a basic attack and every class had at will effects that were better than a basic attack. 5E doesn't use that paradigm and thats the essence of the problem.
Generally it seems you guys want an improved version of the battlemaster ability that is about 3 times better 2 levels earlier. The Battlemaster ability is actually quite good I have seen it used a a lot although they have other options apart from attack granting.
Attack granting might work on a Rogue, action granting doesn't work at all (at least at will). Ironically both mysself and Mearls came up with a high level warlord granting an action to the whole party so the concept is fine not at will though. You're basically granting action surges.
Much like how a Sorcerer devoted to attack granting with haste (and can do other stuff that is around level 10) my suggestion is have attack granting as an option and the warlord can get better at it as they level up. It just solves so many problems like front loading a class and if you focus on it enough by level 10 or so it may not be at will 100% of the time but its going to be close.
And if you want a warlord that does something else you can do that as well. You can compare it with other at will damage buffs in 5E but they have been remarkably conservative in the class designs for it. Its +2 damage at low levels, a daily spell slot at level 2, and extra dice at level 8 for clerics, level 12 option for a warlock (charisma to weapon attack damage), a 2nd attack at level 5 for the martial classes, 6 for the gish classes.
The warlord is basically a support class and in 5E that means not much damage at least at will. Spell casters can nova the damage higher of course and no one is saying the warlord can't have abilities that let them do that either. The difference is its not at will, since the warlord won't be using spell slots that more or less means short rest enabled and short rest stuff is roughly 1/3rd of a daily spell slot.
So yeah the warlord should absolutely be better at attack granting than a Battlemaster fighting but at will is a step to far, 5E is not designed for it 4E was. Its like some people claiming warlord healing should be based around hit dice mostly because that is the closest thing to healing surges in 5E. Why not just grant the warlord a healing surge ability instead of trying to force 4E mechanics into 5E as hit dice based healing is terrible by comparison to a cleric or (bard or druid) for example.
Your action granting suggest did not mention anything about MCing either and the problem is something like a lore bard (which is crap at damage) can splash a level and more or less say "sign me up baby) as a lor bards at will attacks is a meh cantrip and 1d6 +2 or +3 and they get a massive 2 daily spell slots at level 1.
So at will attack granting in general in 5E is a bad idea, its out right terrible at level 1 and even worse if its at will action granting (see 3.0 haste spell).
