Sorry if I’m giving you information you already know: I see you’re using the core horizontal-stack cards successfully - have you tried using core vertical-stack cards instead of the ‘inner’ layout-cards?
For even greater control over vertical and horizontal stacking within a custom-layout card view, there’s also RomRider’s custom stack-in-card, which can be used for both horizontal and vertical stacking, and also can be more easily styled (e.g backgrounds, borders) if you’re comfortable using Thomas Lovén’s card-mod card, as custom stack-in-card has an ha-card element.