>>17810550 (OP)Both qpAdm and G25 can be wrong. qpAdm is not a magic bullet. Before assuming one or the other is right or wrong, you need to understand why.
I can explain G25 a little: G25 admixture analysis is just sophisticated PCA navigation in 25-dimensional space. It has no inherent historicity. Every model you make with a low distance in G25 is "true" but only in the sense that the sources chosen are capable of explaining the position and drift of a target on a PCA. It need not make sense historically. For example, you could model some ancient Europeans as Swedish + Somalian, because Somalian is capable of capturing the drift away from Swedish. But that doesn't reflect a historical truth, only a truth about shifts away from a given position in 25-dimensional space. Basically any given European could be modeled as some degree of modern West Eurasian + modern East Asian + modern African even though this isn't true.