Advice CPU/Mobo cooling with 72mm of height to work with; would you run two fans or one but with a taller heatsink? Which other combo is best?

[CAA]

Hello everyone. First post so please be gentle! I managed to snag a Falcon Northwest Tiki case for my first gaming SFF build. Little did I know the amount of planning that SFF guys have to consider when building in tight places.

My plan is to run a Ryzen 3600 on a Asus ROG Strix X570-i board with "taller" height ram with heatsinks (2x 8GB 3600 CL 16; ~42mm in height) and a PCI 4.0 M.2 drive with a second to be added later if needed.

Unfortunately, this played out in the Asus boardroom:
Q: How many mobo heatsinks would you want?
Asus: Yes

Using tall RAM and the Strix 570-I limits my cooling choices due to ram clearance and the friggeningly large and abundant I/O shrouds and X570-i heatsinks that I would rather not remove (unless they don't do anything to temps). As an SFF virgin, I would like to seek some advice from the almighty and knowledgeable SFF gods on this forum in help picking out an ideal air cooled CPU setup my build and to guide me on my journey to popping my SFF build cherry.

Here is what I have to work with:

• ~72mm Max Cooler Height (not exactly sure as I do not have parts in yet, but from resources from various forums and the fact that the Asetek LC550 used in the current builds require at least 67mm clearance with a report of a 6mm air gap from radiator to pump). The Tiki case is 4" (101mm) wide. Feel free to correct me.
• Tiki case has a 120mm fan mount right above CPU area. I plan to use this as an intake fan.

My initial plan was to run a Thermalright AXP-90 (47mm height) with the stock fan and then add another 120mm case fan on top. The advice I need with this setup is as follows:

1. Running a 120mmx25mm case fan would mean that this fan would be sitting right against the CPU 92mm cooler fan (47mm + 25mm = 72mm!). Is this setup non-ideal due to turbulence?
2. Would running two different fans right against each other in push-push improve or actually degrade cooling performance (decibel readings be damned)?
3. Would a 120mm slim fan be more ideal? This would provide a small 10-12mm gap between the fans.
4. I assume that a 120mm fan with specs leaning towards greater static pressure would be ideal (ex. Noctua P12 Redux).
5. I am leaning more towards this setup because I feel that the additional 120mm fan also will provide additional cooler air for the mobo VRM and RAM.

But then with a little more research I wondered if 1 fan with a taller CPU heatsink would be better. Then came all the Youtube videos and Chinese websites Google had to translate for me. Oh the maddening amount of choices and fan/heatsink combos available and untested! Now I have more questions then answers. I want to pull my hair out at this point.

Now if the above isn't ideal, would the next setup be better?

1. Noctua L9-65 with 120mm fan adaptor (would this even fit the Asus X570-I as the Z390 has issues?)
2. Any other cooler options available that fits my mobo and RAM choice (NH-L12 is 66mm in height and has 43mm RAM clearance but only 1x 92mm fan to cool CPU and mobo)?
3. I wanted to run the ID-Cooling IS-47K with double fans (these would be in a push-pull config with heatsink in the middle) but realized that the Asus X570-I has fitment issues and cannot be used with tall RAM (correct me if I'm wrong)

Thanks in advance. I realize that maybe no one may be able to answer my convoluted questions. It basically comes down to finding the best ratio of airflow to heatsink in a small space.

 

[CAA]

Ok, some updates in case someone was in a similar situation. The term I needed to learn about was "fan stacking." Apparently its more ideal to stack fans in serial with counter-rotating blade directions with each subsequent fan. But fan stacking hardly provides any benefits and can even hurt temperatures after the 3rd or so fan. Plus is adds wear to your fans so it's not a good idea.

The Asus X570-i motherboard really restricts me to non-interfering coolers within 94x94mm spec so 92mm coolers are the only way to go.
I ran across the Shuriken 2 SCSK-2000 CPU cooler. Anyone have any experience on this one? It's basically the perfect height for my setup ( 58mm tall including the 15mm slim fan).

According to one source, this cooler is superior to the AXP-90 Cu (and the L9a of course) that I was considering:
So it's a wrap; if there's no objection or poor reports of performance I plan on getting the SCSK-2000 and replacing the 92mmx15mm fan with a 25mm one (perhaps Noctura P12 Redux or even a 140mmx25mm one) making 68mm total height.