Right, because Aurvandil could TOTALLY have prevented foreign armies from hitting us...
Or, lemme think a second... No, absolutely not. Too many realms in reach of D'Hara, offering ourselves as meat shields would be suicide.
Oh you mean Aurvandil with its 35kcs mobile army and D'Hara with its four cities, one stronghold and two townslands, all of them with fortifications, plus the D'Haran army. Oh yeah, it would have been impossible to make a competent defence of D'Hara.
And we wouldn't need to defend you if we marched are our armies to war against your enemies, besides which, as you even said yourself realms would think twice about picking a fight with D'Hara so long as the strongest military on the continent was willing to defend them.
