I strongly suspect that the primary result of such an algorithm would be very wide error bars on the timeline, and that it would indeed outperform most experts for this reason. You can't get water from a stone, nor narrow estimates out of ignorance and difficult problems, no matter what simple algorithm you use. Though I would be quite intrigued to be proven wrong about this, and I have seen Fermi estimates for quantities like e.g. the mass of the Earth apparently extract narrow and correct estimations out of the sums of multiple widely erroneous steps.
and I have seen Fermi estimates for quantities like e.g. the mass of the Earth apparently extract narrow and correct estimations out of the sums of multiple widely erroneous steps.
Just giving a short table-summary of an article by James Shanteau on which areas and tasks experts developed a good intuition - and which ones they didn't. Though the article is old, the results seem to be in agreement with more recent summaries, such as Kahneman and Klein's. The heart of the article was a decomposition of characteristics (for professions and for tasks within those professions) where we would expert experts to develop good performance:
Static stimuli
Decisions about things
Experts agree on stimuli
More predictable problems
Some errors expected
Repetitive tasks
Feedback available
Objective analysis available
Problem decomposable
Decision aids common
Dynamic (changeable) stimuli
Decisions about behavior
Experts disagree on stimuli
Less predictable problems
Few errors expected
Unique tasks
Feedback unavailable
Subjective analysis only
Problem not decomposable
Decision aids rare
I do feel that this may go some way to explaining the expert's performance here.