It seems to me that this is a pretty arbitrary distinction. I've seen countless times in countless people a stated goal of long term "true will" that ended up not being true at all. Like how people always say Romeo and Juliet were probably mistaking true love for lust.
How can you know for sure unless you've lived an entire life and found the desire in your youth to still have hold?
Also, what did you see that convinced you that someones goal was just an impulse and not true will? How could you tell? Are you accusing people of not being able to recognise it themselves? If so, how do you recognise it when the subject can't?
I think you are over complicating it and I kind of think maybe sharing my view might give some insight into where I, and by extension possibly Iron Wizard, might be coming from.
If you just wanna get drunk and party all the time that's probably impulse. If you have some kind of vision and want to create that vision, that's more of an actual will.
The greatest people in history were not known for their hedonism, but rather their deeds and their effects on society and history. Socrates, Alexander the Great, Leonardo Da Vinci, Newton, and Martin Luther King Jr as some examples. They all had
a purpose.
People often get confused on what True Will is. Crowley spoke of it in terms of orbits. You seek your orbit because it's where you belong... this idea is very close to the ancient idea of destinies as something you are born to do, that you either embrace or reject. True Will in the original sense is when you decide to discover and embrace that through magick. That born to do part is more important than many people realize in some ways, the saying "Satanists are born, not made", while having many meanings kind of came out of this IMO since it recognizes that those called to Satanism realize that they were born with this innate path towards self-realization. The trap that the vast majority fall for though, is not distinguishing their will from their impulses.
Now sure, some people were known for their hedonism, such as Caligula, but they were more "terrible" than "great". And while many great people might of been hedonistic, it's incidental towards what they are famously known for and for what they did that had the greatest impact on the world and history.
As far as Romeo and Juliet, it actually is a good example because they were meant to be portrayed as immature and childish, clearly infatuation based on little more than attraction and not real, understanding and appreciative love. It was meant to be seen as a burden and tragedy for the parents. Shakespeare intended for the audience to see it as a cautionary tale and to feel bad for the families, it was not meant as a tale of actual love. But most people lacked the critical or analytical thought to realize that and only looked at it superficially and over time the newer interpretation stuck.