Better on the second visit, when you stop trying to see everything.
This is a shape, not a schedule. Each day has two anchors and a lot of slack, because 3-day itineraries that book four things a day fall apart the first time lunch runs long. Move things around freely — the neighbourhoods are grouped so that walking between stops actually works.
Paris is expensive enough that budget differences show up fast. Agree early on how many sit-down dinners versus market picnics you're doing — picnics are genuinely one of the best things about the city, not a compromise.