Overconfidence and delusional optimism are (i) ____, so we should rely whenever possible on simple formulas and checklists that measure things strongly associated with a desired outcome. Dumb luck explains a lot more of life than most of us realize, so we must (ii) ___our tendency to create narratives that conjure (iii) ____.

For blank (i) - quite evident, indication is towards something -ve, I guessed the word as "unreliable". Going through the options:
(a) mutually exclusive - out of scope, we are not talking about overconfidence v/s delusional optimism, rather both of them as a group
(b) rampant - meaning unrestrained, growing in an uncontrolled manner => lets keep it because it somewhat goes along with "unreliable" in the sense that OC and DO are so not controllable - cannot be relied upon
(c) antagonistic - too strong a word, its a word which is > "bad" and has a sense of conveying it is "completely against or opposite. So there should be sufficient context to back it up. We only know that OC and DO are unreliable guys whether they completely bad or opposed is beyond the scope
So "rampant" is the better choice

With blank(i) sorted out, lets looking at the interesting ones blank(ii) and blank (iii)

If you carefully assess the sentence in isolation "Dumb luck..." you would find 2 pairs of words/meanings that could make sense

Since dumb luck explains a lot more about life than we realize, we so should:
1. orient our approach that involves luck ("abide by"..."serendipity")
2. not orient always on logic based approach ("beware of".."causality")
"consolidate" & "contingency" doesnt exactly fit the context

We also have the task to connect sentence 2 with sentence 1. Sentence 1 was more about being simple and relying on a formula based approach. Sentence 2 emphasizes a caveat in this. Thus (2) makes more sense rather than (1)

blank (ii) - "beware of"
blank (iii) - "causality"