even if the guess words are correct, the chances of arranging them orderly is 0.9%/100.
It is very easy to descramble a 12 word seed phrase in which all the words are known, and this can be done in under an hour on even a modest home computer. A 24 word scrambled seed phrase, however, will be impossible to unscramble.
Putting aside the increased hassle of longer seeds, isn't it desirable for it to be harder to recover the sequence than it is to brute-force a single address?
If an attacker was going to try to brute force your seed phrase, then sure, a longer seed phrase makes it more difficult for them. But as pooya says, the individual keys will always have 128 bits of security, so an attacker whose best attack is simple brute forcing will obviously choose to target this instead.