Wow nice find, thank you!
EDIT; This has to do with the text posted above:
A: Having descended to destroy the Ark’s samples and research data, the Strogg must first fight their way past the Global Defense Force (GDF) and build a bridge to allow their heavy vehicles (such as the Goliath Heavy Walker) easier access to the biodome. Success here moves the strogg spawn forward, provides more vehicles, and pushes the GDF spawn back.
B: An oppressor-class Strogg (which deploys missile silos, plasma mortars, etc.) must destroy the reinforced biodome doors with its strategic strike gun. Vehicle access becomes more limited, and local infrastructure, such as antennas, support buildings, and storage facilities, forces players to fight on foot
C: Strogg must infiltrate the biodome complex before finding and fragging the research facility below. As infantry faces off under artificial lighting inside, fierce snowstorms limit visibility on the surface.
Compare the map with this and see