Multiple sprites load and placing

Hi! im doing a 2d side scrolling game, the player (a plane) fights with spawning enemies coming from right and moving to left.

To add some dinamism, i made some clouds that also move on the background to the left. The problem started when i separated the clouds in 4, using a multiple sprite, this way i intended to load randomly each cloud sprite spawned.

I didnt have this issue with the enemy sprite since at the moment it is just a single sprite. How can i access to the 4 sprites from the multiple one and load them into my gameobject?

i tought about using a random int (0 to 3) and using it in a switch to load the clouds on each spawn, is this a good approach?

Thanks!