[Sorry for the dissertation; I needed to look some of these up because I wanted to make sure I wasn't messing it up, and I fell down a rabbit hole - it's very fascinating to look at the subtle differences here; at least it is to me, because it also helps my own pronunciation]

It's not nearly that simple. I won't say you're wrong, because you might very well - even probably - be right for some (many even) pairs of German and Scandinavian dialects. But the Scandinavian languages are not interchangeable in this respect, including the Norwegian dialects.

The "clear" ch- start is the "norm" for Bokmål in Norwegian, with the caveat that there is no official Norwegian pronunciation, but in Nynorsk, the IPA used by Wiktionary is /²çʏrçɑ/ (compare /çɪrkə/ for Bokmål) - again with the caveat that there is no official pronunciation and this is a "middle of the road" sort of choice. This is the voiceless palatal fricative, and it's a fairly rare sound and one that Norwegian definitely has in common with German, but the precise variant might not match in all German dialects with all Norwegian dialects.

In Swedish you don't use the voiceless palatal fricative (IPA /ç/ - that's the ch) at all in kyrka - instead /²ɕʏrka/ or /²ɕørka/. Finnish Swedish /²tɕʏrka/ - I don't know whether they use it in any other words. Danish doesn't get even close for kirke (IPA [ˈkʰiɐ̯ɡ̊ə]). So first of all, lets discount those, as I wrote about Norwegian, and while the pronunciation is certainly mutually intelligible it uses different sounds than both German and Norwegian for this example.

I'm also going to mostly ignore Nynorsk, which is also different, and to infuriate any Nynorsk speakers who come across this, when I write "Norwegian", assume bokmål, or to make it difficult "the dialects spoken where Bokmål is the main written language" as technically Bokmål is the written language.

But even within the set of those speakers, you'll find a range going from near Nynorsk to near Swedish or near-ish - but not quite as near - Danish (at least not in pronunciation; in terms of vocabulary we're often nearer Danish than Swedish), with variants in between.

I'm native Norwegian , and I speak German, and it'll sound perfectly fine in Norwegian if you use the "ch" from Kirche at the start of "kirke" - at least the German dialects I'm used with. It will match plenty of dialects, but it might not match specifically your Scandinavian language or dialect. In mine moving towards German "sch" would be very out of place.

I checked some German videos just make sure I wasn't imagining things or have been mispronouncing ch/sch all these years, but the ones I found used a "ch" sound that's perfectly fine at the start of "kirke". You might be pickier than I am with respect that what is the exact same sound, but to me at least, there's a very distinct different position of the tip of your tongue for German "ch" and "sch", and I struggle to even form the word "kirke" if I start close to the "sch" position.

BUT, the drift between the "ch" (voiceless palatal fricative) and the "rs" in "norsk" or "skj" in "skjønn", which in Norwegian is the voiceless retroflex fricative, and that certainly can sound like something in between German ch and "such" but would - as you describe it - be neither, is an ongoing "problem" in Norwegian (that it's "retroflex" means it's pronounced by curling the tongue up like the alveolar fricative used in German "schone" or the palato-alveolar "sch" in fleisch - but not with the tongue lifted towards the hard palate like in both the German "sch" variants; you can shift between those sounds by holding the tip of the tongue in the same position and shifting the back of your tongue up/down - if you speak Norwegian, try switching between "schone" and "skjønn" - your tongue should typically lift at least a tiny bit when pronouncing "schone" and drop for "skjønn" but the difference can be very minor depending on dialect)

My mother used to work in nurseries, and I remember her despairing over the shift towards the retroflex (not in those words...) going back to my own childhood in the early 1980's, as it sounds awful to many of us. She spoke of it as something new the kids were doing and that they struggled to speak "properly", but I'm not convinced it was actually a new thing.

Those sounds are historically very distinct in Norwegian but Norwegian children struggle with separating them. E.g. "kjøtt" is the archetypical example of a word that "should be" pronounced with firmly palatal "ch" (IPA /çœt/) but that people tend to despair over how the pronunciation is drifting towards the retroflex (e.g. closer to "skjøtt") because the mis-pronunciation has become more and more prevalent, and that adults would get really annoyed when kids got wrong.

It's a less pronounced and common "error" with "kirke", but I certainly wouldn't be surprised if it's creeping into that as well in some dialects, so again, to be clear I'm not saying you're wrong; I'm sure you're right for some/your dialect. Germanic/Scandinavian dialects are just infuriatingly diverse.