Bit confused with this. Electrum only has a 12 word seed. The nano ledger s has a 24 word seed. So wouldn't just having half of the nano ledger seed which is 12 word seed essentially the same thing as having no word in an electrum seed?
No, because the entropy size is a power of 2 number which is growing exponentially. And after a certain entropy size the entropy is considered secure. 12 word mnemonic offers 128 bits of entropy which is secure and more importantly it is offering the same exact level of security as a bitcoin private key (key for a 256-bit elliptic curve which has 128 bits of security).
Cutting 12 words in half is cutting your entropy down to 64 which is not as secure anymore.
This is the difference:
264 = 18446744073709551616
2128 =340282366920938463463374607431768211456