Rapp has only wild white suam (non-Stalsbergi) in his stock, but not red suam. Apparently, they have not found the collection point of the original red sauum that were imported decades ago that became the aquarium strain. In most GT literatures they describe red suam as an unknown species from an unknown location. I am curious what the wild red suam looks like when they find it.
If your wild scalare are twice the size of domesticated angel, they may not be scalare. A recent tropical fish magazine I read identified a dozen new angel fish species versus only 3 in the past. One species has naturally red color and the other has blue/green that are candidates for line breeding into colored angels.
(On the other hand, I haven't always found wild fish to be more aggressive. I currently have some wild Peruvian scalare that are actually pretty mild, milder than the domestic silver angels I initially had them with, even though the wilds were twice the size of the domestics.)
If your wild scalare are twice the size of domesticated angel, they may not be scalare. A recent tropical fish magazine I read identified a dozen new angel fish species versus only 3 in the past. One species has naturally red color and the other has blue/green that are candidates for line breeding into colored angels.