Did your post include the reasoning for fuses at the battery? I'll reread.
And I still don't understand how you post the great pictures.
Safety!! The fuses at the battery are to protect any wiring that directly connects to the battery and could potentially chafe or otherwise short out somewhere. House banks can deliver massive amount of current, many banks are easily in excess of 3000 amps. In a dead short situation this is very likely a boat fire.
I had this happen on my 2005 Catalina due to sloppy factory wiring. ABYC E-11 requires fuses for a "house" bank but there is no requirement for a battery fuse on a start bank. With the typical 1/2/BOTH/OFF switch wired directly to the starter this is a rather odd omission for start batteries on small boats with small motors. This is made even more ridiculous with Catalina shipping the vessel with two IDENTICAL 4D batteries were either bank could the the house bank and either bank could be connected to the starter but just one bank is fused.
I have gone around and around with John Adey at ABYC regarding this, and even he agrees personally & ideally that all banks should be fused, but it has been to hard to craft language to meet all scenarios. At some point you hit engines where fusing start banks becomes so expensive and difficult that it' not feasible and a sheath or conduit protection is a better solution.
On small AUX diesels this fusing is however is a non-issue. Due to the E-11 requirement Catalina uses just one ANL fuse. When I bought the boat I simply added one for the "start/reserve" bank as well.
Long story short the wire from the common post of the batt switch to the starter shorted and chafed on the diesel motor as it came out of its conduit chase. Luckily I had a 250 amp ANL battery protection fuse on that circuit. The short literally took a chunk of metal out of the motor like a welder could. Without a fuse it is likely our brand new vessel would have burned to the waterline.
That is why I fuse banks...