What does the tactical team turtle shell mean?

Tactical team turtle shell is a defensive language in the game. Tortoise shell is a defensive language in the game. It means that some players purposefully stick to a special or important area with various props or equipment. Just like a real turtle. These players hide in the built "shell" to stop the enemy's attack. But the price of this tactic is that the team that carries out this defense has no chance to fight back. The result of this tactic is a long-term stalemate between the two sides in a certain area. In the game, this tactic refers to the behavior of many engineers building many turrets and supplying for defense in an area.