In short, when you have groupings of obstacles, start with the easier ones, and make them higher or greater as they continue. Keep increasing the degree of difficulty. Or they can take several minutes to overcome. Generally speaking, when you have two or more obstacles in close proximity, they should be progressive. Obstacles are just as important as opponents for generating conflict.
Obstacles provide variety and surprise.
They can create or intensify tension and suspense. And they can demonstrate the talents and tenacity of the characters who encounter the obstacles. A screenplay without sufficient obstacles would be an obstacle to character development and to audience enjoyment.