It's sort of like (though on the complete other end of the spectrum) that Mussolini established Corporatist Fascism, and then Naziism, Falangism, Shintaisei, Estato Nova, Clerical Fascism, Austro-Fascism, etc. all emerged, but, despite notable, and often very substantial, differences from each other, they were all built upon, and inspired by, the Fascist ideal that came out of Mussolini's National Fascist Union, which effectively formed, as a newspaper before it was a party, in 1915.
Judging a party on its merits, and on its values, is for me also looking at the internal processes in that party.
The voting democracy in that party and the genuine openness to deliberating discussions. the degree of distortion of those discussions by tactical positions of infighting, the degree of finding common ground that reflects a consensus of thoughts within the party.
The semi-fascist party PVV of Geert Wilders in the Netherlands has "solved" the issue of internal party politics cq internal party democracy, by reducing the political party association to 2 members: Geert Wilders himself and another association having 1 member (Geert Wilders). The first decision of that association was BTW a member stop.
He did this to avoid internal infighting getting newsmedia coverage causing voters loss (all other semi-fascist parties in NL before him inevitably broke apart in those fierce and uncompromising infightings).
When I meet people voting on the PVV, I use in between the normal arguments this totalitarian aspect of the party with amazing success.
The latest new semi-fascist party FvD of Thierry Baudet has BTW again many members in the party association.
The SP, the populist left wing Socialist Party, a former Maoist splinter of the former CPN, Communist Party of the Netherlands applies the Maoist model for internal party democracy.
The CPN applied the normal degenerated Marxist methods of party democracy a la USSR and was taken over in the 70ies by my generation youth and after a tedious long battle the authoritarian leadership was eliminated from party influence. That new CPN merged with other far left splinters into what is now GreenLeft (which has a good internal party democracy),
That democratising process led to the SP splintering out of the new CPN.
(as a person I do have however a lot of sympathy for the SP because of its strong efforts in workers/living standards and especially community efforts. It is BTW so in the SP that chosen politicians do give their full salary to the party and get back a living allowance at a pretty low wage level !)
Several attempts by the socialist and social democratic parties since already before WW2 to aim for a polarised parliamentary politics (the Westminster model) all drowned.
If not because the majority in parliament was not achieved because the voters preferred multiparty.... the polarisation model failed because the party members did not like the internal backfiring of polarisation.
Because once polarisation is applied to conquer the majority in a parliament, it is ofc also used by factions in a party to conquer the party leadership and party direction, at the expense of a true internal party democracy.
Coming back on those pre-WW2 fascist parties.
In NL we had the NSB, the NationalSocialistMovement. The most striking characteristic was that it was seen as a virtue among members and followers to NOT to deliberate, NOT to discuss about the party direction and thoughts.