I have reached a mission in this campaign in which objective is "Clear a path through..." which most probably means annihilate all. The player does not start with a shaman (builder) even though there are fields at the starting location. It seems the task is to destroy enemy units and structures using a very small provided force. One of the ways into enemy base is free from turrets but Sen-Soth there has 3 Gene-Labs and pumps out units constantly. When that area is attacked, the opponent will also bring in army from the north which outnumbers the player's force. To add insult to injury, enemy creates flyers but player does not have anti-air weapons.

Is there anybody who played the campaign? Is it possible to complete it or the game's funds ran out during making of this mission and it wasn't even playtested?

I kept trying to pass this mission.
Eventually I tried doing it very slowly and after a while reinforcements arrived, which included a builder.

I'm not sure if there was any trigger other than time, so if you just wait it out long enough you'll get reinforcements and you'll be able to pass the mission.