Its certainly more efficient to let war pull. That's not up for debate. But fi you are in a random PUG thing, it is often better to just say "I know wtf im doing so I'm tanking 20DPS be darned". Expecting the other tank to pull and swap it after 10 sec in a pug and do raid level meta is a bit optimistic in my experience. I save the fancy stuff for my raid static. Suboptimal is not only OK in lower level content, but often the smoothest way. Sure you can do zero tank stance in a rando pug for ex primal farms, but I can also ensure the groups odds of winning go up by spending some time in defiance and not trusting some pug healer like I trust my static healer.

Optimal play at all costs is not always the 'right' decision, and even if you don't, the side effects are minimal. Loosing smidges of damage here and there don't matter if you are a good player with high uptime and deal with mechanics properly in a pug. Fundamentals are the most important and suboptimal safe play can make runs much smoother. This isn't talking about being suboptimal because youre lazy. Its being suboptimal to be safe in pugs which is quite a different thing. Bringing the pro level raid meta attitude to everything in the game isn't always going to be the best decision.