I don't know much about DC100, but, to me, open world means there are multiple choices and multiple things going on. Hooking them from B2 to DC100, that feels like a single funnel? From point A, go to Point B, although that path might have 3 diff variants, they all end up in the same place?
I try to give players in a new campaign 3 different things to do. 3 hooks/paths. 3 factions. 3 locations to explore (whether a dungeon, outdoor setpiece, another town) and a homebase.
You can make each of those 3 things another module. So DC100 for 1 hex/location after B2, and two other modules for two other locations.
Then put them in their home base (a village or perhaps even the Keep from B2) and dangle those hooks to each of the locations - rumors, someone actively recruiting, a physical object pointing in a direction, etc...
That's just how I would do it and have done it.
You had said "Allegedly they can shoot down Russian planes, because their targeting systems have longer range."
My post was to share information to indicate that is not so - F16 does not have longer range.
The rest, you and Tom are in agreement.