I can see a big issue at the bottom of all this:
If the planetary formation process is purely Chaotic, then the process is highly sensitive to the initial conditions. These conditions may end up determining the outcomes, which we observe today. And today, the outcome most obvious, across the Solar System, is the diversity of planetary environments within a comparatively tiny volume of space.
Monitoring the buildup of the extraordinary diversity of the environments we observe amongst the Solar System planets and then beyond to exo-environments, would then become a key scientific focus area.
If the count of planetary environment diversity starts to look like a bottomless pit, then our perspective on what it takes to get life started, (perhaps also a Chaotic process), may also be hugely broadened (ie: well beyond those we presently have).
If it takes way more environmental diversity than we currently imagine to get life started, then perhaps the common view that because the universe is so big, the chances of exo-life must be enormous, is vastly moderated. The rationale would be that maybe it takes a universe of the size we see, for one instance of life bearing environments to occur. And the alignment of diverse conditions, may just happen to occur rarely, in a given large volume of space. The particular alignment of the right initial conditions for life has happened at least once. Our problem is in trying to extrapolate from this instance without fully understanding the scale of numbers of non-life bearing environments, and then, the scale of of numbers of life-bearing environments. The parent population (the sum of the two) may just add up to what we presently see in our observable universe.
The more instances we see where things like planetary magnetic fields, perhaps not being the sole driver behind the presence of an atmosphere, the more we may start to emerge from what I feel may turn out to be a very narrow, myopic perspective of how life bearing environments may actually come into existence.
The perspective provided by Chaos Theory, suggests that many initially complex processes and elements spontaneously result in emergence of self-organisation, and that this emergence is sensitively dependent on the initial conditions, from amongst what might be a huge array of diverse environments.
The above thinking, (I believe), also fits in nicely with all the known Laws of Physics and Biological/Evolutionary processes. The only thing I can think of at the moment which stands in the way of this, is our present classical, fully deterministic thinking, inherited from our education systems and, perhaps, the classical physics eras.
At this is all in my humble, speculative opinion, of course - and discussion is most welcome.
Cheers
