No, they don't need to be identical at all. As long as they are of appropriate size, and allow the snake to feel safe when in different thermal gradients in the cage you are fine. I have had snakes who wont even use their premium hides, and would rather be under a piece of paper towel, haha.

In the wild these snakes would wedge themselves into unused burrows, under tree stumps and basically anything they can find to feel snug. Definitely no uniformity in nature. Hides can be anything you want as long as they are correctly sized and easily cleanable. The snake isn't going to care if they look different.