I absolutely agree that it would be daft to depend on Wiki, but there are so many different sources coming from different angles available on the internet, it's possible to get a wide range of opinions, and use your own judgment.
Given that statements by Collectif Nemesis are also available directly, first-hand online, as are factual reports about their actions, it's possible to look at those and make your mind up, at least provisionally, about what they say and do.
For instance, I think I've researched enough evidence - their origins, personnel, links to existing parties, etc - to reliably identify them as being on the far right of the political spectrum, and to feel that their commitment to women's rights is probably a temporary strategic one, which is useful for them politically. I'd be sceptical about them protecting my rights as a woman and a lesbian if they got into power.
I suspect that they would probably strategically take up any cause, e.g. animal rights, with the same vehemence, if it could be used to promote their politics, it happens to be women's rights that serve them well at the moment.
That's the vibes I'm getting about them having read various sources, but Other Vibes Are Available
Nothing about them detracts from condemnation of the attack on the man at the demonstration.