Firstly, budo is not "monkey see monkey do". Smart monkeys think. Secondly, "aliveness" is not just a physical thing, but more so a mental attitude. So, I see nothing inconsistent with Matt Thornton's words and how you choose to incorporate that into your own training.... even if you come from a "softer", more "fluid" style of aiki.
actually no, I"m sorry but that's just not accurate. You may wish to run an argument that there is something called "mental aliveness" and that it can be effective or whatever. But to claim that substituting menatal aliveness for a fully resisting training partner is consistant with what Thornton says, is just plain wrong.