He's definitely a better wrestler than Frank, and he's stronger. He's fought the best at HW, LHW, and some of the best at MW. He could definitely use his wrestling ability and power to get a decision victory over Shamrock.
The only way I could see Shamrock winning is if he pulled off a submission. He isn't gonna KO Hendo, Hendo has fought better strikers who couldn't pull off that task. The only 2 sub losses Hendo has had was to each of the Nog bros. I think Shamrock could pull off a sub, but it would be very tough. Hendo has nice sub defense.
I like Frank Shamrock and all, but the guy hasn't fought anyone of any consequence in awhile. He's living off his past fame and taking easier fights.