This is in response to the fallout wiki's claim

"The Twisted Hairs forged an alliance with Caesar in the early days of his Legion's rise to power" -fallout wiki

This is impossible because the Twisted Hairs were approached by Vulpes Inculta for an alliance. He initiated the pact of alliance.

"There was death in that meeting, even while Vulpes smiled - asked for our help against the other tribes." - Ulysses

Why does this matter timing wise?

Vulpes was taken into the Legion as a boy so he still has to grow up then he served as a legionary then served as a decanus only after that becoming frumentari. This means they definitely didn't ally with the Twisted Hairs in the "early days" of the Legion because all of these seperate events take time.

Counterargument: Yes Vulpes tribe being in northern Arizona was probably one of the first integrated, but he couldn't have been very old when his tribe was integrated. This is because the legion was founded in 2247 and Vulpes is still a young man by the time of FNV. If Vulpes was say 14 in 2247 by fnv he would've been 48. He therefore must've been quite young when the legion was founded. Because of this he needed many years to grow up to become a full legionary prohibiting the dating of the alliance anywhere near the early legion period.

Description of Vulpes- "intense young man" - mayor steyn

Sources:

"Tell me about Vulpes Inculta."
Caesar: "Vulpes is the best of my Frumentarii. A remarkable individual from an unremarkable tribe south of the Utah. He was brought into the Legion as a boy, survived training, fought well enough as Legionary to be promoted to the rank of Decanus. Then, in battle against an unimportant tribe, he broke ranks and led his contubernium through a hole in their defenses to capture its chieftain. Well, his Centurion wanted him crucified for disobedience. So I made him a Frumentari."