What's the difference in actual chassis length? What is the actual difference in rake angle? From a chassis design standpoint, you have a minimum COG, so if you tilt the engine in the chassis you can play with that COG. Rake angle is just plank rake, it isn't necessarily chassis rake. Granted the floor itself has to follow the plank, but what about the stuff above the floor, does that need to follow the plank?
If your car has less rake, if you want more rake you have to redesign the front end to accommodate that, likewise, if you plan to run more rake, the rest of the car has to be modified to facilitate that. Mercedes has spent all of its development tokens at the front of the car. Perhaps they're planning to run more rake next season? Although they're already running rake, so it could be to allow them to run even less rake.
Other teams may not be able to do that, or not willing to do that. Mercedes can it has a nice advantage, I just hope it pans out because until now Mercedes has had a development advantage which has hidden their missteps, however each misstep allows others to get closer. If they make one from here to next season and others claw back ground they won't be able to react in time.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee