I'm not sure I like this jungle analogy, but in the analogy, I guess my point is that some laws "expand" civilization and "shrink" the jungle. They reduce the accessibility of "lawlessness" on the part of the government. You're right, they can always still get there, but they make the jungle further away, make it harder to get there.
It's simply not true that we'd know if the GG was being influenced by the monarch. If the GG decided to use reserve powers (or consider using them and decide not to, like they did in 2008) we would have no way of knowing whether the King of England was behind it or not. And if your thought is "it doesn't matter we'd remove any GG or LG that tries to use any power at all" you're obviously incorrect about that :P
I'm not saying a law, like the proposed one to abolish the HRT, would be passed in secret. I'm saying the political pressure would be secret. Of course the law must be passed publicly, and you'd have all kinds of yelling on both sides about it. In the alternative, if parliament passed something and the GG refused to give royal assent, likewise that would be very public. The influence on the GG, however, would not be!
I would love to imagine that any constitutional crisis would be resolved immediately in favor of democracy and not on the basis of the underlying issue but I think that's very hopeful. I'm not sure how to make it more clear...I could come up with more hypothetical situations to demonstrate where the king could exercise undemocratic influence, but I don't know why that would help! I'll try one more and then I'll leave it if this doesn't help explain what I'm talking about:
Let's imagine a parliament with a thin liberal majority, but it's expected to flip soon due to some unpopular decisions. Parliament narrowly passes a law that the residence at the Citadel of Quebec is going to become a public museum operated by the federal government. The Conservatives hate this because they consider it a waste of taxpayer dollars. The King privately opposes it because he quite likes having a vacation home in Quebec (and the GG actually uses it, so maybe she feels the same way). The GG doesn't give royal assent, but says it's for some technical deficiency, expecting an election to remove the issue...or alternatively simply says outright that the Conservatives are correct and the government can't afford it...or somesuch mildly-plausible excuse that the milquetoast canadian middle class will accept (I only suppose the thin liberal majority in order to make this plausible excuse, but you could certainly imagine others if the liberal hold on parliament was strong). If the GG does not give royal assent...you think we'd go into a constitutional crisis? I don't think anyone would think it's worthwhile (which, of course, means that such a law wouldn't pass...which is its own kind of influence being exercised passively by the Crown!).