I think Zemmour is basically legitimate as a person. He's been in this for too long and isn't someone who has... cohenveniently cohenverted... to a position Rightward of RN to play some role. I don't know anything about 'Eric Striker' other than that he's routinely lambasted as a NazBol by the few content creators who I do follow and that he's involved with TRS.

Now, the question is whether Zemmour's sudden rise is actually genuine or whether he's just being used, e.g. blackmailed, or simply being egged on without realizing he's being played, in order to serve an agenda of some sort. That agenda would be obvious: Keep Macron in power or (admittedly much less likely) give someone even more disastrous like Melenchon a more serious shot where he otherwise wouldn't have had it. Without Zemmour, after all, the election result would be quite predictable: First round, Le Pen #1, Macron #2; second round, Macron #1, Le Pen #2. But maybe the political classes, bureaucracy, pro-EU types that support the Volt parties around Europe, etc. are just playing safe—from their point of view, Le Pen coming #1 in round two would be like restoring Vichy France. They're obviously wrong, but that's how they view it as Left or Left-leaning paranoiacs who suffer from what one might call extreme cases of 'conservaphobia' or 'nationalphobia', and who think Marx was well-intentioned and guiltless like Juncker and some other EU bigwigs do, and who see a massive asymmetry between Far-Left and Far-Right because of their Left-ish biases (e.g. the Far-Left is misguided, bad for business, etc. at most, but the Far-Right is downright analogous to a political Satanism).

I am also skeptical of Zemmour because he has no party behind him. So unless people can rally around him and institutionalize quickly after he is elected, it seems safer just to hope that the RN gets normalized instead. Otherwise, he might serve as a kind of Trump-style (remember the 'Trump slump') release valve who simply pacifies our French brothers and at the same time leads to further radicalization and unification of the Left. The French Left's biggest weakness is how many parties they have split into (PS, PCF, LFI, PDG, EELV, etc.). If they united tomorrow they would easily defeat Macron and anyone Rightward of himself. For example, if Hamon alone stood down in the last election, Melenchon would have faced Le Pen in round 2 and Macron would not have become President. In party politics one has to break into the top two or three parties and ensure they stay there, so getting RN to replace other 'Right' parties like LR seems the best macro-level option. Furthermore, consolidating a new party of the Right will be extremely difficult. For starters, literally everyone will assault this new party (Left - motivated by Zizek-style paranoia, a Zemmour party makes them fearful of a (non-existent) supposed Rightward shift; Right - motivated by self-interest, a Zemmour party could steal their voter bases).

I expect Zemmour to fade away back into his usual activities after the election—in which case I will feel particularly vindicated in my assumptions about the man. However, if he does well it may also remind RN that the seemingly commonsense logic that the 'Centre' is electorally the best position to stand in is in fact erroneous and leads only to losing more Rightward voters than it picks up Leftward voters. There may only be a few 'satisfactory' choices in round one (Le Pen, perhaps Zemmour, Dupont-Aignan, the Christian Democrat Party was oddly perhaps best on social issues, but worse than the other three on matters of borders/immigration, and we have to prioritize the latter over the former because we have a time limit to solve it). Either way, only Le Pen or Zemmour might make it to round two. Macron is throwing a few bones to the Right before election time, but is obviously garbage. Bertrand and Melenchon are both garbage. Some Leftists are calling for all Left candidates to stand down bar one (which may win them the Presidency), but they are probably too divided to pull that off. At the very least PS (candidate currently undecided) and PFI (definitely Melenchon) will put up separate candidates. However, I would like Macron to come third to a Leftist because Le Pen or Zemmour could easier beat Melenchon.

We should also be under no illusions about Zemmour's popularity. Indeed, there is Harris-Interactive as cited somewhere by Ethnocrat: Macron 55%, Zemmour 45%. But there is also Elabe: Macron 63%, Zemmour 37%. But Harris-Interactive has Macron 53%, Le Pen 47%; Elabe has Macron 60%, Le Pen 40%. The takeaway from both is that Le Pen has a marginally better chance (+2% Harris-Interactive, +3% Elabe) of beating Macron than Zemmour.