I have to say also the 25 minutes who take maybe are a wrong calculation, because what if he was "lucky" to find the order on 25 minute, but you need to make more and more tries to find out the average time, not only one disorded seed.
It's actually pretty accurate.
On my home hardware attempting to descramble a seed phrase from 12 known words, I can test around 115k possibilities a second. 12! / 115,000 = 70 minutes. Given that on average you need to attempt 50% of the possibilities to find the correct one, the average for me to descramble a seed phrase is 35 minutes.
But yes, your other points are correct. It is a pointless scenario because the security of your coins should never rest on an attacker having access to your seed phrase but being unable to descramble it.