Sure (only have the one for the first lore book)
Three with adventurers:
Rhitahtyn sas Arvina: "The adventurer then led a small unit into the innermost sector [...]"
Assault on Castrum Meridianum: "[...] the selfsame adventurer who slew Rhitahtyn sas Arvina once more took charge of an elite adventurer unit. They stole past the defenses of Castrum Meridianum [...]. Yet again the adventurer and his allies emerged triumpahnt.
Curiously at Ultima only the adventurer was mentioned: "Yet by the grace of Mother Hydealyns blessing the adventruer was spared death."
Interesting note: The lore book states that only our Wol survived the battle of carteneau while the rest perished.
Steps of faith: "[...] suggested instead that the scions make every effort to assemble a contingent of elite adventurers - a volunteer force under the leadership of the Warrior of Light."
Without others:
Ifrit: "However by the power of the echo, that holy gift bestowed by Mother Hydealyn herself, the adventurer proved immune to Ifrits tempering [...]. Flying into a rage Ifrit attempted to slaughter the adventurer, only to find himself outmatched."
"With the adventurers victory over the beastman god [...]...Word quickly spread of the valiant hero - the eikon slayer - spurring others to seek to enlist his aid and that of the scions.
Titan: " And so, in a moment that shall forever be enshrined in the annals of Eorzean history, the adventurer slew the Lord of Crags [...]"
Garuda: "Admidst the whirling winds, the adventurer succeded in striking down the Lady of the Vortex, only to see her rise once more [...]. "
Mog: "At the behest of the Order of the Twin Adder, the warrior of the Light journeyed to the Twelveswood, and with the cooperation of the moogles, he sought out and confronted the Mogglesguard and their liege lord [...]. Though hard-pressed the adventurer won the day [...]"
Leviathan: "[...] the Triumph, towed the Whorleater in the sea, along with the Warrior of Light, to confront the fell primal. And so it was that folliowing a titantic struggle on the high seas, he succeeded in vanquishing Leviathian [...]"
Ramuh: "[...] elected to suspend judgment until the Warrior of Light himself underwent a trial by combat. Thus was he forced to strike down Ramuh and in so doing earn the right to champion the cause of peace in the Black Shroud."
Shiva: "The resurrected saint of eld lashed out with a righteous fury, pushing the Warrior of Light to his mortal limits..yet the battle ended as it had begun, with the young maiden kneeling in the snow, cursing his ignorance [...]"
Nabriales: "[...] he escaped with both Minfilia and the relic she held and the Warrior of Light followed. In that otherwordly void the adventurer defeated his Ascian foe and rescued Minfilia, returning all three to the Rising stones."
Bismark: "From this selfsame island the Warrior of Light then launched his offensive against Bismarck and like so many before the Lord of Mists soon fell to his might."
Research Facility: "While Alphinaud, Ysthola and Estinien kept the forces of the VIth Legion occupied, the Warrior of Light procceeded toward the "ARF" alone. [...] There the Warrior of Light fought and defeated Regula van Hydrus once more, and delved deeper into the heart of the floating isle and towards his quarry."
Lahabrea and Igeyorhm: "In a bid to eliminate the adventurer, the Ascians attacked as one, but with Hydealyns blessing restored, they were no match for him."
Thordan: "How the Warrior of Light managed to overcome such impossible odds taht day, none can say. History only states that in the end, he prevailed, and was the first man in Isghardian history to arrive in the city upon dragonback"
Trials of Hraesvelgr: "Thus convinced, Hraesvelgr declarred that he would put the Warrior of Light and his compansions to the test. Within the ruins where Ratatoskr once dwelled, the three weathered the trials of the great wyrm [...]
Nidhogg: "With it, the Warrior of Light became Ishgards best and last hope of slaying the rampaging Nidhogg. The great wyrms shade was a fearsome foe, consumed by a thousand years of vengeance. However, the Warrior of Light too was a force to be reckoned with, infused with the might of Hraesvelgr and filled with an otherwordly determination. Thus empowered, he subduesd Nidhoggs shade and restored Estiniens to his original form."
_________
So they made it very clear in the lore book when a unit of adventurers were with us (the last one being steps of faith). This for me means that at least those that wrote the lore book wanted to make sure to point out that we did have help (mostly against Garlemald) but did the primals alone. If its canon that we did have help everywhere then why not write it down in the lore book itself, especially since they had no problem with writing it down when it matters. This for me is the evidence that we did most of it alone (which also makes much more sense for a lot of examples ingame too)
I am not sure how the second lore book is with that (thus the stormblood expansion) and I also could not find hints towards 24 man raids. If those are described in lore books with more people then I have to accept that in some cases even there we suddenly get a bunch of adventurers with us.
In the end ARR and HW was done mostly solo.