I dont know. The Venusian can muster far more ships which gives them a exploring advantage ad they could do pirating which stalls the other empires. They could also get lucky and have a heavy star behind theyr Jump-point.
Mmmm.
A couple of points:
1) the venusians had the smallest starting fleet (only 6 Ktons, compared to the humans 144 Ktons of warships).
2) the venusians have the smallest starting shipyards. By mid report, the venusians had built an additional 14 Kublai, so by the end of the report, they would have had ~34 Kublai (or 34 Ktons of warships). Over this time period, the humans had built an
additional 84 Ktons of warships (to a total of ~230 Kton).
3) the venusians have the lowest tech.
So while the venusians may have the largest fleet in
numbers, they are being out-built, out-massed, and out-teched.
Sorry to say, but the only way they can come close, is by relying on luck.....