Actually, the thing is, the gospels are an even bigger problem than Mein Kampf or The Iron Dream. (Yeah, I've read them both.)
The problem is that, distorted as that may be, you still get a soemewhat coherent image of what Hitler was supposed to be like or about in the author's view. You can't come out the other side of Mein Kampf thinking, for example, "nah, he really liked the Jews. You have to take it in context, man." Nor, "you know, he really had no problem with the Versailles Treaty."
But for the gospel Jesus and the HJ reconstructions, exactly that is the problem. If you cherrypick the right mix, he can be anything, never mind that such reconstruction contradict each other. In one place he's like a progressive pharisee, and then you turn the page and he blasts the pharisees for no longer executing children who give their parents lip. In one place he's all humble and comforting to the poor or even washes the disciples' feet himself, in another he not only allows a woman to humiliate before himself all evening, but berates his host for not doing the same.
It also doesn't help that Jesus doesn't actually have any characterization or personal growth or anything that would help anchor that. As IIRC Ken Humphreys points out, and he's not the only one, Jesus is an automaton. Or as I like to use the modern trope, a
Black Hole Sue. It's a collection of very short stories that really have no plot at all. In fact they just follow the following pattern:
1. (Optional) Some minimal setting the scene happens
2. Jesus arrives
3. (Optional) Someone says something minimal to trigger his doing the next step
4. Jesus delivers his pronouncements
5. Everyone is instantly amazed or angered
6. Jesus moves on
And especially step 5 is invariably the most unnatural kind of reaction. Not only nobody asks more questions (except maybe to set the scene for Jesus's next pronouncement) or raises some obvious objections, that would allow us to glimpse exactly what was Jesus thinking on the topic, but they occasionally even just forget what they were doing. E.g., the whole village marches Jesus a couple of miles to chuck him off the nearest cliff (because that's where the nearest cliff is, from Nazareth) in Luke's version of prophet with no honour, but then suddenly Jesus just walks away, and nobody even thinks to say a "hey, come back, we ain't finished rolling you down this hill, mister!"

Or even forget they just saw the same thing happen verbatim before (see the two feedings of the multitudes) and dutifully are amazed again.
I mean, even Hitler tells you (the version he wants you to believe of) what's his problem with the Versailles Treaty, or what tactics he uses to get people to nod through, etc. That serves to anchor that reconstruction, distorted as it may be. If anyone thinks that, see, he really liked the Versailles treaty, you can look at the text again and go, nah, then he wouldn't have said X, Y and Z against it, or forget to say anything in favour of it.
But that's missing for Jesus. He just arrives, gives a pronouncement, everyone is amazed or angered, he leaves. He never gets to actually debate any topic, nor explain what he has against it, and you never get either show or tell about how he came to hold those opinions.
There is nothing to anchor such decisions about which parts he really said, and which parts he wouldn't say, other than reflecting the personal biases and wishful thinking of the one making the reconstruction. You can't go, "well, he probably didn't actually mean they should execute children, but was just trolling the Pharisees, because <insert other piece of character development that would make it unlikely>".
So in that aspect he's a much more blank page than either version of Hitler in those books.