One issue I see with your criticism is that "But they didn't do such a thing in OTL" is a point commonly used.
So what if they didn't OTL? This is TTL.
That should be the slogan of this site 😂
ATL to OTL is the same as fanfiction to canon.
It depends on how far you push it. People sometimes will write Notzi alternate history where Hitler or whoever is in charge acts sensibly and isn't an anti-semitic genocidal racist. That isn't plausible at all, and it sometimes is people not so subtly using it to push their wehraboo wet dreams. You'll also see Confederate victory scenarios where the slaves get freed later on without any of the "bad feelings or racial antipathy from OTL reconstruction." That was never going to happen.
This, though, doesn't particularly strain belief. Mussolini was a guy given to changing his mind on stuff and it's not like Italy becomes a racially enlightened, non-brutal democracy.