Oh I re-read the comment again and realized they are suggesting part-time lower-income PLUS paternal leave higher-income. That's weird on multiple levels: You want, as you said, optimise for total income; and you want to spend as much uninterrupted time with your kid as possible.

This option gives you neither.

Rather, I have a colleague who took paternal leave with their partner and afterwards switched to part-time for a bit.