Jason,
It happens all ways. We sometimes get called in and see that a land planner has already prepared a land plan giving us a general idea of what they want. Usually we get a chance to improve it from a golf standpoint. Every so often, we are offered the job providing we don't change the land plan and routing whatsoever. I declined one of those once, early in my career, and a name designer took it as offered, and went on to develop several more courses for that same big time developer.
In some rare cases, owners do want the golf to come first. In places like Atlanta, both can be accomodated on best land, because the golf holes usually work best in the valleys and houses above, where they get views.
One thing most don't consider is that there are broad areas the developer cannot use, and those are where the golf cousre must go. The typical areas are floodplains, of course. However, sometimes we are told to use an area where the topography would make it difficult to get sewers and water lines to work well. Golf is often used as a buffer between houses and factories, or garbage dumps or other land uses not compatible with houses. And of course, golf usually provides a buffer to power lines and houses. For that matter, the golf course often divides the housing types and neighborhoods in a subdivision - often we see apartments/townhouses on the first 400' back from a main highway, then fw, then the single family homes.
Each project is obviously different in its requirements. I had one (built, now closed) where I worked with a land planner. I took the first run and showed three concepts - single fw with houses on both sides, double width fw, each with houses on one side, and then one with more of a core course, with only a few fingers of golf getting housing frontage. I fully expected the developer to want the single fw scheme, but the land planner and he both argued that while they lost immediate frontage, they felt the overall community was better with the double loop feature. So, who was I to argue?
We also consider the views to golf from streets, and minimizing road crossings for golfers, among other things.
There's more, but you get an idea.