Worms have been placed pretty equally btw. he had just a little advantage there but you got first turn and could eliminate this advantage.
And i wouldnt call it underground, its more like midground 

I was talking about 13:00 minute of the game when Liav was already at the top, dominating the entire map and bringing me down to my knees (press Spacebar to skip turns to reach this moment quickly). I wasn't talking about the start of the game. Why would that even matter who has 1st turn?  The one who starts might have their crates stolen or might be hijacked. Tus mole has never been about who climbs faster but about dominating the entire territory, connecting all worms, cutting off your enemy from all the crates, and being heavily armed which Liav succeeded in to the maximum by 13:00, maintaining all 4 worms alive, key positions, and the biggest arsenal imaginable.

That's the time when he became a monstrosity in the battlefield. We aren't talking about 00:00 time, Pinky