[Boromir88]

I have to admit that I’ve never particularly understood how the Ring was especially helpful in this regard. It can’t create soldiers out of thin air and how does it entice people to follow someone else to their death they know little about and have no history of loyalty toward.

It could very well just be the deceit of the Ring. Some had accepted the Ring's deceit (Galadriel and Sam) and rejected the desires of 'glory' and 'army flocking,' where others (Boromir) fell to it.

Going back to the famous Letter 246:

In the “Mirror of Galadriel”, I 381, it appears that Galadriel conceived of herself as capable of wielding the Ring and supplanting the Dark Lord. If so, so also were the other guardians of the Three, especially Elrond. But this is another matter. It was part of the essential deceit of the Ring to fill minds with imaginations of supreme power. But this the Great had well considered and had rejected, as is seen in Elrond’s words at the Council. Galadriel’s rejection of the temptation was founded upon previous thought and resolve.~Letter 246

The 'Great' knew what the Ring was about, and knew their thoughts of overthrowing Sauron militarily wasn't the right strategy. So, they rejected this plan, and Galadriel passes her 'test.' Same goes for Sam:

In that hour of trial it was the love of his master that helped most to hold him firm; but also deep down in him lived still unconquered his plain hobbit-sense: he knew in the core of his heart that he was not large enough to bear such a burden, even if such visions were not a mere cheat to betray him.~Tower of Cirith Ungol

The Ring filled Sam with thoughts of being 'Samwise the Brave' leading armies to overthrow Sauron, and after he could make the Gorgoroth into some grand and beautiful garden. But, Sam knew very well that the Ring was out to betray him, and even if it wasn't, he didn't want what the Ring had to offer him anyway...what he had was good enough:

The one small garden of a free gardener was all his need and due, not a garden swollen to a realm; his own hands to use, not the hands of others to command.~ibid

Boromir, it's just a little different:

'What could not a warrior do in this hour, a great leader? What could not Aragorn do? Or if he refuses, why not Boromir? The Ring would give me power of Command. How I would drive the hosts of Mordor, and all men would flock to my banner.~The Breaking of the Fellowship

Eventhough if he knows what was said at the Council of Elrond, that doesn't mean he accepts what was said:

'Were you not at the Council?' answered Frodo. 'Because we cannot use it, and what is done with it turns to evil.'
Boromir got up and walked about impatiently. 'So you go one,' he cried. 'Gandalf, Elrond - all these folk have taught you to say so. For themselves they may be right. These elves and half-elves and wizards, they would come to grief perhaps. Yet often I doubt if they are wise and not merely timid.'~ibid

I think at least during this age where the numbers of the West were greatly diminished compared to prior ages, then a military overthrow of Sauron was impossible, even with the Ring. And this was something that was debated thoroughly throught the Last Debate, and prior. They had not had the military might to challenge Sauron, the Ring had to be destroyed. Or Sauron had to be killed, as he came out in the Last Alliance, and openly challenges Elendil and Gil-galad. But, I doubt Sauron's going to be leaving Barad-dur anytime soon:

Denethor laughed bitterly. 'Nay, not yet, Master Peregrin! He will not come save only to triumph over me when all is won.'~The Siege of Gondor

I do find it interesting though that Tolkien explores another way of Sauron's ultimate defeat:

'But that of course did not destroy the spirit, nor dismiss it from the world to which it was bound until the end. After the battle with Gilgalad and Elendil, Sauron took a long while to re-build, longer than he had done after the Downfall of Numenor (I suppose because each building-up used up some of the inherent energy of the spirit, which might be called the 'will' or the effective link between the indestructible mind and being and the realization of its imagination).'~Letter 200

So, just kill Sauron enough times, and he would not have the 'will' that it took to reform again...as each rebuilding takes up part of the 'will.' But, again, the only victory at this time during the War of the Ring would come if the Ring was destroyed.

So, long story short, I'm agreeing that the West had lacked the military prowess to overthrow Sauron (even if Aragorn had the ring). So, any sort of vision of rallying these grand armies was just the deceit of the Ring. And Sauron wasn't going to come out of Barad-dur anytime soon, so I doubt he was going to be slain as he was in the Last Alliance.