Brank
The small number of earthlike planets in the outer regions, or even the whole STE territory shows they really didn't choose a great place to set up shop.
Barren planet after barren planet the Zerg pass, and unless they want to use some cave bacteria as soldiers, there really is nothing of interest here.
Many of these worlds seem to have been once earthlikes however, but as a measure to slow any TIE advance back during the NH TIE war, these planets have been completely decimated, some cold due to nuclear winter, some merely bombed into becoming a desert, the scorched world campaign clearly was a success.
Many of these worlds have fake civilian broadcasts matching that of new tau...
Before any further progress could be made into STE territory, the systems surrounding the main mass of zerg report high scale FTL wakes, followed by numerous very cold ships appearing on long range scans.
The zerg's main advance is now surrounded by these signatures, rear guards and those a few jumps behind notice the same cold signatures blinking in and out of existence by the nearest star.
However the main advance groups have no signatures in their system, instead the signatures lie in wait one jump or so ahead.