Correct. Decterum never actually fought against the St.Luciens, although their was rivalry, nothing really happen.
Also, the Second Human-Dwarven war after the Human Exodus, under Carrion rule members of the Decterum Order, including the current Lord Marshal at the time, Ailred Ruthern, led a band of Knights to the Dwarven capitol and interrupted the Dwarven-Coronation of their new King (Whoever Spuller was playing at the time) which basically led to large hostilities between the two nations and resulted in the revival of the war.