ALW doesn't mention Patti's competitors in "Unmasked" (his excellent autobiography) but mentions she was vocally on top of the competition even though his notes were "Warmth? Diction?" They had originally planned on Elaine Paige opening with the role but Equity made it a definite "No" in February of 1979.
He also takes credit for ensuring that the 6 show week for the Broadway Eva with an alternate in place for the other 2 performances was the rule as in London. He mentions the irony of demanding that rule only to find Patti claiming in her own autobiography that the score for EVITA was clearly written by a man who hates women.
He also shares a very supportive letter he wrote for Patti during the out-of-town tryouts when the feedback on her performance was not-so-hot. He clearly had admiration for her and knew she could pull it off.