The key point is that Hudson didn't need to spend a penny on these things. Merely expressing a slight intention, and people would gather them to present to him.
The benefits of power were fully demonstrated here.
These were just a part, if anyone delved into the expeditionary army, they would find something amiss with those so-called "Engineer Corps".
Although they appeared to be civilians, they were in fact various kinds of craftsmen. In turbulent times, these people might not attract attention, but during post-war reconstruction, they would become sought-after talents.
Even if they were discovered, it'd be no issue. They were all carefully selected by Hudson himself, and he certainly would not let them go.
Given Hudson's current status, unless someone was out of their mind, they would not try to overpower him.