There's the flaw:
Render farms don't speed up rendering, they distribute animation frames to speed assembly.
Cinema 4D, for instance, only does single frames even if distributed in a render farm.
While it takes advantage of multi-processor machines, individual frames aren't shared between machines.
You might remember the old days with Archicad's infernal rendering engine that a rendered image could be assigned to several machines according to line number, or stopped each morning at a specific line number for a multi-day rendering. The resulting strips would be assembled in photoshop. In the old days, when a decent rendering took a week of night shifts, this is how you used your machine in the daytime.
Those days are gone. Now a machine performs a global illumination, radiosity or ray-traced "solution" like a crystal, and renders the scene from the solution. One frame at a time.
Dwight Atkinson