Amusingly, a post mentioning only one viverrid species

and four non-viverrids.
As a matter of fact, mongooses are closer kin to hyenas and euplerids than they are viverrids

as the latter group is basal to all three of the former groups. The Nandinia (or African Palm Civet) is basal to all other feliform carnivores, including cats.
Your count in the above list of European public collections was
slightly off; the following is closer to the mark (with corrections in bold):
Eupleridae:
Spotted Fanaloka (2)
Northern Narrow Striped Boky (9)
Grandidier's Vontsira (2)
Fossa (30)
Eastern Ring Tailed Vontsira (8)
Herpestidae:
Yellow Mongoose (91)
White Tailed Mongoose (1)
Banded Mongoose (
92)
Meerkat (546)
Marsh Mongoose (2)
Egyptian Mongoose (8)
Dwarf Mongoose (
88)
Common kusimanse (21)
Slender Mongoose (7)
Nandinidae:
African Palm Civet (3)
Viverridae:
Masked Palm Civet (10)
Asian Palm Civet
(43)
Small Toothed Palm Civet (2)
Small Indian Civet (1)
Binturong (
77)
Banded Palm Civet (
1)
Owston's Palm Civet (5)
African Civet (12)
---
Rusty Spotted Genet (6)
Pardine Genet (
2)
Feline Genet (2)
Unknown Genet sp. (2)
Haussa Genet (5)
Common Genet (
57)
Cape Genet (20)