The fact that you think it takes "fitness in your arms"....whatever that is, to swim a 24 minute 1500m shows you haven't a clue what you are talking about. BTW - a good 10 year old boy can swim that fast. It only takes fitness to swim a 1:40/100 if you are a shitty swimmer (based on technique). If you have reasonably sound technique 1:40/100 is a nice all-day cruise pace.....kind of like walking. I say this as a guy that considers himself to still be a shitty swimmer, but seem to come out near the FOP in the swim in most races. I am about a 1:05 40K TT and 21 minute 5K guy.
Just because you don't like the guy or the TI method doesn't mean he isn't correct in the larger picture. The methods are different, but the message is the same.