After playing a lot of rounds on the 2s version, it seems the map is marine based, or aliens just need to know how to play it. Aliens have to be *very* aggressive on marine nodes from the start. Typically what happens almost every game is marines enter maus hive (aliens start tau\angel's) and get a PG up. A lerk gasses said PG and the aliens spend the next few min trying to get them out of maus since marines sort of gravitate there. Meanwhile another PG goes up in one of the empty hives since one marine snuck over there while the aliens were distracted.

Even if aliens manage to clear maus hive finally, they still need to be very aggressive on their nodes during this whole process because they can hold at least 4 of them relatively easy.

Marine easy nodes (almost automatic):
Marine start
Barren
Arrival
Northern

Easy - Medium:
Circumn
Central Node Descent

Hard:
Tau
Maus
Turning Point
Angel's

And even those except maybe 2 are easy to hold if you own a PG in one of the vacant hives. Although having this many nodes usually guarantees marines getting proto tech which sometimes can lead to a longer game, but that is the exception.

I'd say remove the central node descent node and put it somewhere more friendly for aliens so they can hold 4 nodes somewhat easily so they can even out a little versus marines. It seems every game I've played the most aliens could hold was 3, unless you count The Pit, but if they have a phase in Tau Ceti is a cakewalk to take that node down quickly, and then walk right into maus hive.

If its still an option, remove (at least) one of the easy nodes for marines and give it to the aliens.