You're ignoring correlation. The twin towers are, for almost all purposes, virtually identical, and experienced largely identical scenarios. For them to behave differently under such circumstances would be less extraordinary than for them to behave similarly.

To my knowledge, the twin towers are the only buildings in history to have been hit with a four-engine plane full of fuel (El Al Flight 1862 apparently had only two engines left when it struck the apartment building. Note that the building fully collapsed at point of impact). Again, to my knowledge, with WTC 7, they were the only high-rises to have experienced serious, out of control multi-floor fires for hours after receiving major structural damage--Deutsche Bank received serious damage but no fires so far as I can tell.

If 100% of similar structures in similar circumstances have failed in a similar manner, is that improbable?

Then we're veering off the "multiple coincidences" hypothesis, to a much more probable theory.