This whole discussion feels like nobody watched ENT.
The Federation exists because Archer was such a fantastic mediator. Add in his rapport with T’Pol and Shran, and his willingness to die in the place of a Tellarite ambassador, and it’s little wonder he was able to knit the beginnings of this alliance together.
I really got an Archer vibe from Pike in “Spock Amok” (SNW S01E05), when he dealt with the R’ongovians.