So if I create a list of every combination
from a to zzzzz, I get a very short seed:
julkt jtqbf hhocl qhtic bezsh kvgba
So 12,356,630 "words" gives 23.56 bits per word. 132/23.56 gives 5.6, which means 6 word seed phrases.
But I'm amazed Electrum can just restore this seed phrase without the seed words!
The important point to note is that an Electrum seed phrase is not converted back in to the entropy which generated it, or broken down in to bits, at any point. Unlike BIP39 which does require a fixed and known wordlist so it can convert your words back in to bits in order to verify the checksum, Electrum's version system simply hashes your words as they are and uses the first 8 or 12 bits of that hash.
After this, in order to actually start generating private keys, the next step (for both BIP39 and Electrum) is to feed your words as they are in to HMAC-SHA512, alongside salt of the word "mnemonic" (for BIP39) or "electrum" (for Electrum) concatenated with any passphrase. So again, no need for Electrum to convert your words back in to bits. (This is also why you can import BIP39 seed phrases with unknown wordlists in to Electrum. Electrum will warn you it is an unknown wordlist and it cannot verify the checksum since it cannot convert your words back in to bits in order to verify the checksum as I've explained above, but it can still feed those words in to HMAC-SHA512 and generate master keys and subsequent child keys.)
But yes, I'd highly recommend nobody does this. Understanding the principles of what is going on is all good, but you should always stick to the standardized methods.
It's 10 years from now and one of your words was Brabble.
And you go to recover your seed and it just does not work.
Doesn't matter for Electrum seed phrases - Electrum does not need to know the wordlist used. For BIP39, even if every copy of the BIP39 wordlist was lost forever, you could still recover BIP39 seed phrases, you just wouldn't be able to verify the checksum.