First, let's just dispel the idea that none of them has any "fixed, correct" plurality...

Note that it's much the same for us as it is for them, and any other animate/inanimate group whom/which we might think of, including OP's grammarians. Grammatically, both these are fine...
1: There are grammarians in this room, but none of them has the right to prohibit this usage
2: There are grammarians in this room, but none of them have the right to prohibit this usage either
As the above links show, singular and plural are both perfectly common. Idiomatically there are some context-specific preferences - plural "none of them like me" is way more common than "none of them likes me". Perhaps because people saying that are thinking more of how many people don't like them.
The other issue raised by OP's examples is that...
3: He is an American
4: He is American
...are both perfectly valid (#3 is a noun usage, #4 is adjectival). But...
5: He is a grammarian
6: ?He is grammarian
I've marked #6 with ? because grammarian can't be used adjectivally like that. The few results in the link at #6 are a relatively uncommon construction involving deleted articles before nouns within lists.
TL;DR: OP's examples (d1) and (e1) are both fine. In both cases, the grammatical/syntactic "subject" is none of them, which can be treated as singular or plural according to stylistic preference. It's irrelevant whether them refers to grammarians or Americans (or example sentences, come to that).
d
ande
seem to be incorrect.none
in this cause isplural
, in the same logic that0
is plural.0
horses
, rather than 0 horse. Additionally, the wordAmerican
here is anadjective
, and as such should beAmerican
, notAmericans
. There are three phrases you can use:There are grammarians in the room, but not one of them is an American
.There are grammarians in the room, but not one of them is American
. Or,There are grammarians in the room, but none of them are American
. – Rob Oct 24 '14 at 8:29