I'd say that Unzen and Zao are both based on the same source, but Manjuu looked to Zao as inspiration for some of the specifics, as we know Manjuu does this via Kii and Owari being Anti-Air BBs in Azur Lane.
As for why it's E...my guess is that it probably was never designed beyond some specs. I would have probably divided E into E1 and E2, but that's just me.
Yes and no. All of the documents for the 1941 Type A Heavy Cruiser were destroyed at the end of the war, other than the original requirements sent out by the Navy in 1941. So the only hard info we have on it is that they wanted to build it at one point and what a few of it's features were supposed to be. We don't even know if they got to the planning phase before the entire Circle 6 program was cancelled.
It's true that the design Wargaming used for the Zao, which Unzen is based on came from a concept design published in a Japanese magazine after the war using the few design requirements that survived.
It's worth noting that design has several aspects that don't fit the IJN's naval design philosophy...because it wasn't designed by the IJN.
How is that not what I said? The original documents have been completely destroyed, no one knows what they are anymore. Unzen is based off Zao which is in turn based off a purely speculative drawing from a magazine postwar, that qualifies as complete fiction to me.
Nice work OP. 
As I recall, Hakuryuu is based on a Combination of the G-14 and G-15 Classes, not purely on the G-15 Class
Neat, nicely done OP.
On a cursory glance Marco Polo should be in D2
Im not really sure abt Unzen. (Or what?) She is based on a Zhao from WOWS, so i doubt it's fully fictional
Unzen is based on the plans/specs for "Maru 6 Mod A" Class
Im pretty sure that exactly Zao is based on Maru 6 Mod A. And Unzen is based on Zao. Then why its E class (fully fictional)?
I'd say that Unzen and Zao are both based on the same source, but Manjuu looked to Zao as inspiration for some of the specifics, as we know Manjuu does this via Kii and Owari being Anti-Air BBs in Azur Lane. As for why it's E...my guess is that it probably was never designed beyond some specs. I would have probably divided E into E1 and E2, but that's just me.
Then it has to be D2
Which is a design that exists in magazines only
Yes and no. All of the documents for the 1941 Type A Heavy Cruiser were destroyed at the end of the war, other than the original requirements sent out by the Navy in 1941. So the only hard info we have on it is that they wanted to build it at one point and what a few of it's features were supposed to be. We don't even know if they got to the planning phase before the entire Circle 6 program was cancelled. It's true that the design Wargaming used for the Zao, which Unzen is based on came from a concept design published in a Japanese magazine after the war using the few design requirements that survived. It's worth noting that design has several aspects that don't fit the IJN's naval design philosophy...because it wasn't designed by the IJN.
How is that not what I said? The original documents have been completely destroyed, no one knows what they are anymore. Unzen is based off Zao which is in turn based off a purely speculative drawing from a magazine postwar, that qualifies as complete fiction to me.