Um fator era a dificuldade que Eragon teria de reconciliar seu papel como o novo líder dos Cavaleiros do Dragão com sua lealdade jurada a Nasuada e suas profundas conexões e amizades com os elfos (e anões). Ele diz isso em Herançap. 804-805:
"Eragon! What are you thinking! You know you have to join. All of the magicians who serve me have to. There can't be any exceptions. Not one! I can't have people think that I'm playing favorites. It would sow dissent among the ranks of the magicians, and that is exactly what I don't want. As long as you are a subjeect of my realm, you have to abide by its laws, or my authority means nothing. I shouldn't have to tell you that, Eragon."
"You don't. I'm well aware of it, which is why Saphira and I have decided to leave Alagaësia."
...
"I don't understand."
...
"It never would have worked for me to take charge of the magicians. Saphira and I have to raise the dragons and train the Riders, and that must take precedence before all else. Even if I had the time, I couldn't lead the Riders and still answer to you - the other races would never stand for it. Despite Arya's choice to become queen, the Riders have to remain as impartial as possible. If we start to play favorites, it will destroy Alagaësia. The only way I would consider accepting the position would be if the magicians were to include those of every race - even the Urgals - but that's not likely to happen. Besides, it would still leave the question of what to do about the eggs and the Eldunarí."
Na mesma passagem, Eragon também lista vários outros fatores logísticos para sair:
A necessidade de barreiras físicas para defender os dragões, mais importante a distância
A necessidade de manter os dragões alimentados com gado que não seja de fazendas e caçadores de anões
Mas então Eragon revela a razão mais importante para sair, um pouco semelhante à primeira razão que mencionei, mas com uma reviravolta - não seria certo para ele ficar, mas não por causa dos problemas de lealdade. Como ele diz:
"I've become too powerful. As long as I'm here, your authority - and that of Arya, Orik, and Orrin - will always be in doubt. If I asked them to, most everyone in Surda, Teirm, and your own kingdom would follow me. And with the Eldunarí to help me, there is no one who can stand against me, not even Murtagh or Arya."
"...because I have this power at my disposal, I have a responsibility to act...If I was wrong, though, who could stop me? I could end up becoming Galbatorix, despite my best intentions...My presence here unbalances things, Nasuada. If I am to avoid becoming what I hate, then I have to leave."
TL; DR: Não era apenas medo da segurança do dragão, era a necessidade de deixar as terras livres de sua influência, para não ser governada por outro Rei Cavaleiro. O fato de haver também questões logísticas, de segurança e de lealdade estava apenas no topo do bolo.