I haven't read this entire post but would you consider all the different natural intelligences in the world today different architectures? Would you consider different humans as having the same hardware (with exceptions) but different software? Can intelligence be created or exist as a individual entity independent of the existence any other intelligent entity? It seems likely to me that it could only exist as a social artifact even if only as a set of clones interacting, learning, and diverging independently, or only in relation to its human creators. It also seems human selection pressure would be weak compared to natural pressures and lack of pressure would translate to a lack of advancement.