Choosing a new gimbal and tripod for my R6 and R5

I've been searching for a tall tripod and am ready to pull the trigger and buy the Benro Rhino 24C . One of the reasons why I selected this brand is that I'm also in the market for my first gimbal head and have selected the GH5C Carbon Fiber gimbal head.

My question: I noticed that the base mount diameter of the tripod is 46mm and the base mount diameter of the gimbal is 60.4mm. Should the gimbal head (or any other head for a tripod) be smaller than the base mount of the tripod? I might have thought they would be compatible being made by the same brand?