Is it a mistake in AD725 and other datasheets?
The order of RC is irrelevant if using SMD caps. If using THT caps then use R 1st  to reduce path length for stray capacitance over a ground plane which has higher stray capacitance (lower impedance is good).

The R value is always 75 and prevents the C value decreases slightly due to spectral range is higher for Chroma.