I noticed that the chrono second hand and the split second hand are not in-line. This demonstrates the possible effectiveness of one the new changes in the 5204: Patek has taken care of the matter that big forces are working on the split and chrono hands ...
The hands are correctly aligned in the photo. The bottom split hand has a wider bottom than the top one. The top one aligns on the midline and the bottom one is slightly wider on both sides at the bottom. Both then rapidly taper to same width on the rest ...
That the hands are differently wide is something I can not judge or see as I do not have any of the two watches. The "play" of the hands is mentioned in reviews and as you are saying are an essential part of a mechanical watch. Speaking for both watches: ...