Re: How long to crack 24 word phrase if you know all 24 words out of order?
At any rate, I wouldn't advise scrambling the words as a safety measure, tempting as it may be due to the above. The focus should be on keeping the seed physically secure and easy for the owner to recover.
Yeah, this. If you cannot be sure that the safe location you have chosen to secure your seed phrase will remain safe, then your options are either to find a new location, or use one of the standard procedures for adding additional security to your wallet, such as:- Use a multi-sig which requires compromising multiple seed phrases to steal your coins
- Add one or more additional passphrases to access the majority of your coins
- Encrypt your seed phrase
In all scenarios, the additional information you need (other seed phrases, passphrases, decryption key) should also be backed up on paper and stored in a separate safe location. Whenever people try to roll their own security by scrambling words, applying some sort of home made cipher, etc., it commonly leads to them forgetting what they've done and losing access to their coins.
The point it to understand how difficulty (time estimation) changes when we change length of seed - they say size does not matter, but we clearly see the longer the better 
Well, I wouldn't necessarily agree with that conclusion. There is no good reason to scramble your seed phrase, and I would go as far as saying that you shouldn't be storing in a way which means scrambling is even a possibility. You shouldn't be aiming for a longer seed phrase because it is more difficult to unscramble - you should be focusing on keeping your seed phrase safe.[/list]