I love Angle. I really do. In terms of a combination of technical ability and raw power, there is no better in-ring performer than Kurt in my eyes. His match with HBK at WM21 might just be my favourite match of all-time, along with Hart/Austin. But I honestly can't vote for him over Inoki, and I feel the main thing working against Angle is, surprisingly enough, the match stipulation.
Angle's best work and biggest success within WWF/E, ironically enough, came when he was a heel. This is the time period he was defeating the likes of Steve Austin, The Rock and Triple H, among many others. While he definitely had success in his face runs, it was his heel runs that left his lasting legacy on the business; there's a reason "You Suck!" was so popular for the majority of his run. It's therefore safe for me to say that prime Angle was heel Angle.
With regards to an ultimate submission match, which combines the durability one needs in an Iron Man match with the necessary of submissions in a typical submission match, both stipulations strongly favour the babyface, particularly with regards to a decisive match, which I consider matches in the WZT to be, not feud enhancers. And Inoki is a guy who, to my knowledge, was almost exclusively a huge baby-face. If Rikidozan were the Lou Thesz of Japan, Inoki was the 80's Hulk Hogan; wildly beloved and victorious in almost all of his major feuds.
I have enough confidence in Angle as a wrestler and performer to say he will get a submission, maybe two, out of Inoki; as a testament to Angle's expertise in submission wrestling; after all, he's made several other huge stars such as Undertaker, HBK and Lesnar, among others. However, given that Angle's prime was as a heel, Inoki's was as a face, Inoki's expertise in submission also, and the bias that faces are given in these kind of matches, I think Angle taps the mat more than Inoki in this match. It pains me, because I love Angle, but Inoki is not only the more likely wrestler to win this stipulation, he's also the more decorated in terms of wrestling accomplishments and influence.