In order to get collision with a 40% chance on a set of 2 ^ 80 addresses, you need a memory size of 2.4 * 10 ^ 25 bytes. And even applying algorithms that use a trade-off between memory and calculation time - it will still be a huge size.
That's not correct.
Floyd's cycle-finding algorithm can be used to find colliding script hashes with O(1) memory, for just a factor 3 slowdown.