Ah, I see. For cumulus clouds (ie, "broken") we only pay attention to the base altitude of the layer, and allow our physical model of cloud growth to take care of the thickness of it. But we do model in some variation to the bases of the clouds as well - and the clouds themselves vary quite a bit in size and shape. So it's not really possible to position a cumulus cloud layer at a precise altitude and still have it look realistic. It's just the trade-offs we chose to make there.
However I do suspect this may be worse with ASXP, because I believe they limit themselves to 3 layers. So if they really want multiple cumulus layers close together at similar altitudes, they don't have a way to convey that information to us. FSGRW, and RWC used alone with X-Plane's default weather system, can both represent unlimited numbers of layers and so this is less of an issue in those scenarios.
Be forewarned you're likely to encounter a lot of tribalism around weather add-ons on the org. But if you learn anything useful there please let me know. I stay off the org for my own mental health!