hey how do you complete this level? I keep losing because of that damn shrine and I can never build enough tier 1 tanks in the turn limit

I rushed fusion cannon tech and then built 8 or so to conquer the area. Buying the relevant techs from the skirineen really helped, but i still had to savescum near the end to manage.

Ah, that obnoxious level where Tarth win on turn 30 if you do nothing.

I went back to my old save games to refresh my memory. Here's how I beat the level:

===
turn 5: colonized 2nd territory "Pleasant Plains", closing the gap between me and Tarth, and have planted my 3 tanks (laser canon) there while I built laser towers. I'm doing zero research at this point - too energy intensive.

turn 10: took 2 more territories, and now have 4 territories in the upper left corner of the map. I'm getting defensive, with 3x laser towers in Pleasant Plains, and 3x more in Steamy Mesa. These territories face the Tarth, and I don't want to invite them to attack me. I've got a fusion plant now in Chcht landing, and have turned on the tech lab (you start the game with it). My automated factory is mostly money making (5 colonists), but some steel (1 colonist).
(Research) I've researched automation, molecular, fusion canon, and am progressing on chaos computers.

turn 15: ChCht landing is really ramping up - a factory, shipyard, and second power plant (nuclear for now). I'm building power plants in most territories, anticipating tech labs. I've built an airport and will build another soon (both in that territory to the upper right). Building cultural centers, to upgrade to museum.
(Research) synthetic fertilizer, currently SAM troopers, and next will be hoverway then neutronic fuel.

turn 20: I'm looking at 3x shipyards (for income) and 6x laser towers in Pleasant Plains. Defense + income there. I have 2 airports in .. steamy mesa? Most important, I've attacked Dreary Marsh and took it from the Tarth! Note that territory borders on the territory with the shrine. With 2 attacks I could reset the 30 turn clock. But I'm building up for another attack. I have 3 tech labs and extra fusion plants to go with them. I'm building 4x laser towers in my first turn in Dreary Marsh.
(Research) synthetic fertilizer, currently on SAM troopers, and next will be hoverway then nucleonic fuel.

turn 25: Took the shrine! 4 fusion canon survived, and 6 SAM troopers. I'm betting I had 3 airplanes that died during combat, as only 1 remains. Airplanes tend to be distractions at this point: my troops fight the front of the colony, while the rear half of the colony takes down the airplanes. Looks like I have 12 laser towers in Dreary Swamp - that lets me fling my army forwards without bothering on defense.

===
In roughly 10 turn increments, I expanded for 10 turns, researched and built income for 10 turns, and then spent it all on a few attacks during the last 5 turns. By turn 25 I've interrupted Tarth's hold of the shrine, but I have 8 credits left. Even if I lose that territory... I get another 30 turns before I need to retake it.

Good luck with the 4th level of the Ch'Cht campaign, it's one of the more difficult ones thanks to the 30 turn deadline.