They need to secure it in stages.
Stage 1: The first venture should be securing the hoard, cus it is currently just sitting there for anyone that can get to it, to just take it. They need to block off entrances to the loot and get a trustworthy security team to guard/patrol. And setting up a temporary base camp near the entrance.
Stage 2: Next setting up a more permanent base camp for dwarven resettlement and reconstruction. Establishing a safe route and building a secure warehouse for processing and appraising.
stage 3: Expanding and fortifying the above. Forts, roads for wagons, vaults ect.
Did anyone ask for my analysis on this? Probably not, but this is just my 2cents that I had rattling around.