Hmmm… Interesting problem…
You mention “Anderson Connection”, while Yeti claims “Power Pole Connection”. Anderson’s are terrible connectors and known for oxidation problems, and they may or may not be compatible with the Yeti. Most likely Yeti sells there connectors separately.
Fuse blocks typically only deal with the positive side, but some, not all, also require the fuse block to be grounded.
IF all of your accessories are grounded to the chassis, then you simply ground the negative power pole to the chassis. IF any accessory isn’t grounded to the chassis, then a separate ground wire needs to be connected back to the negative power pole.
MOST fuse boxes have a single, heavy, 12v positive going into them, which should be fused according to wire capacity, then it will go through the individual fuses, and then out to the accessories. It’s relatively simple and straight forward.
The power pole connector on the Yeti is only rated at 20 amps, so you’re going to need to be very careful to not overload it. Therefore I would put a 20 amp fuse between the Yeti and the fuse block. Use 25+ amp wire between the Yeti and the fuse block. The wire size should always be greater than the fuse size.
"Proper Planning is preferable to premature failure" ~ DreamLife