He meant that you should use those slvl1 Lances to Break Limit the slvl 14 one. And then get even more of those SR Assaults from Dark Disaster, the Guns.For Anubis? It's a bit more complicated than that. I've made a
damage calc for this.
But you're so new that you probably won't have much of an option other than picking whatever is your highest base Atk Eidolon. I don't know if it's even worth for you to calc anything yet. I guess you can calc if Tiamat or Jack would be more damage output for you. Jack has such low stats that it'd probably be Tiamat, just as a guess.