Population Migration / Travel
With the plague gone, many religious figureheads now argued that it was originally sent due to excessive warring between those who believed in gods. Although this did not sit well with many, it still made it hard for leaders to start new wars. Now devoid of the original purpose their god had given them, the hobgoblin tribes set out for new battlegrounds.
The hobgoblins had originally settled in the northern tips of the Savage Isles, but after the plague subsided they had been left without a purpose. Now that no more battles were taking place on the Savage Isles, they migrated south. Here they found the war against the Holy Order of Druids and quickly involved themselves.