Imp test provided some decent information on last and how players navigate first to second, in particular the flow of players heading underground. Evidenced by @Idolon there's a perception this is meant to be upward style. This is a failure on my part to properly direct players underground. The above ground isn't meant to be a main route like upward, but instead a minor flank that puts attackers at risk of getting caught by a respawn wave. The focus is entirely underground. To emphasise this, I've opened up the main entrance to underground, added a ramp near that entrance and added signs/shifted cover to draw eyes to the entrances. I playtested A1B for a couple hours and after a teams second or so attack they learned to play almost exclusively underground. I believe the route issue is how players learn the map. It doesn't teach the player about the underground in a natural manner. Thanks for the ideas @theatreTECHIE again. On top of that I've opened 2 additional attacking entranced to last. It should be a much more level fight now. If this fails, then I will revisit the design of aboveground.