Habitat first, park second
Birding itineraries should be built around habitat transitions. Kenya makes that easy because the habitats sit close together, so a route that looks inefficient on a map is often the one that produces the longest list.
We pair birding groups with specialist guides rather than general safari guides. That is the single biggest variable in the final count, and it is worth more than an extra day.
The days themselves are different too: earlier starts, later returns, shorter distances, more time with the engine off and the roof hatch open. A standard game drive schedule does not suit a birding trip, so we do not use one.