This topo map and the Roach map show the route staying on the ridgeline once the saddle is reached - this is incorrect, the trail actually stays below and to the south of the ridge until the ridge turns south again toward the summit.
If you read the route description, then you saw that it describes the trail below the ridgeline. The topo drawing is meant to be a general guideline to point you in the right direction. As you know, the trail below the ridge is very evident and a topo map is not needed once you get to the saddle. Feel free to delete your comment. Thank you.
Actually, you should fix the map or call out this discrepancy in the route description. There is no reason to provide erroneous information to hikers - San Luis is not a technical climb, there are plenty of beginners, and they get confused easily. Which is why we met up with people who had gone the wrong way up the ridge, and why I made the comment in the first place.
I have made a note at the bottom of the route map.
However, I must point out that even in an outstanding guidebook like Gerry Roach's 14ers guide, the route drawings are not exact. In fact, my map and Roach's map indicate the same route on San Luis Peak. Maps and route drawings are intended to be as a guideline. There is no way a map or route drawing can pinpoint the exact route. Climbers are expected to use common sense and are sometimes required to do route finding. Route finding is part of mountain climbing and is what makes it an adventure. Although the route and trail on San Luis is pretty straightforward, a nice class 1 route like on San Luis is an excellent opportunity for beginners to learn a little route-finding if needed. I must point out that thousands of people (including me) climbed San Luis Peak successfully prior to my putting that map/route on SP.