if each word was picked randomly.
Again, the words aren't picked. Entropy is used to generate a random number, and that random number is encoded as a seed phrase.
If the random number is generated in a cryptographically secure way, then yes, the probability is the same. The point I am making is that I don't believe the Javascript function
crypto.getRandomValues within a browser environment (as is the case with Ian Coleman) will generate truly cryptographically secure numbers.