I apologize in advance for I am not aiming to be contradictory but instead view this as an exchange of our ideas and perceptions, however differing or not they might be.
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I am not sure what above mindset you are referring to and whether it is that mindset that you are immediately summarize below... as to how you understand it.
IMHO, generalizations extending to all fast predators and anything that startles them at any time are dangerous and better be stayed away from. None of the these three generalizations are true in our communal experience. Pertaining to my measly ATF experience, if this was true, I'd lose all 40 or so of them in the first days or weeks, which has not been the case at all. Yet, agreed, after 2-4 years, I have lost like 75% of them.
About biting instead... When ATF are startled and hence stressed I think it is the farthest thing on their mind to bite any tank mate. I think they bite not out of stress of being spooked but either out of stress of unnatural proximity and competition or out of stress of hunger. Thus, I cannot agree with your wording in this spot either.
Nor do I agree with the statement of no alternative. As mentioned above, there are at least three known alternatives I can think of - a round tank, pond, and ideally soft wall pond.
The ATF final exhibit is planned to be one of the two - either a 26'x5'x2' made from conjoining six 240 gal glass tanks of 8'x2'x2' or a 40'x4'-6'x4' (varying width) made of acrylic, which has been already bought, and the glue too...