This would be a rough tough one ! Who takes it ? I have a leaning towards Greb,but it would be very close.
Dreadful match-up for Matt. As in Conteh I, Harry would be playing for the decision. Unlike John, he stays on his feet until the end. Attrition was Matt's game. That didn't work with Greb. Saad Muhammad didn't have the defense necessary to hold down Harry's scoring. Greb had proved 20 round stamina. Matt would be a bloody mess long before the final bell, but he would definitely get there.
I'm going with Saad here, it would be a war, but I think at some point, Saad's power is going to get to Greb, it will probably make it to the final bell, but Saad will pull it out.
**** it, I'll take Matthew Saad Muhammad as well... but not because of some "human progression" newer is better bull****! Greb could be beat and especially by a tough LHW. A prime Muhammad (Matthew Franklin/Maxwell Loach) stands 5'11" with a 75" reach and walked around at 185-190Lbs while still in good shape. He wasn't stopped until his 37th fight and after nearly 8 years as a pro (LKOby10) to Hall of Famer Dwight Qawi who was a LHW and CW Champ and even fought at HW. It was pretty much downhill after this. He beat Marvin Camel 1 out of 2, lost a split-decision to Eddie Mustafa Muhammad, beat Marvin Johnson x2, beat Yaqui Lopez x2, beat John Conteh x2, and beat Murray Sutherland among others. Greb was only 32 when he died but he had about a million fights (boxrec lists 299). He was 5'8" with a 71" reach and was a bit smallish at LHW. With 20 losses, 17 draws, and 2ND, on his resume (he was even stopped twice) it's not hard to imagine Greb not winning a fight... even though he won 260 times. I'm not taking anything away from Greb... just saying that a win for Saad Muhammad is possible. I like what I've read about Greb (and seen, if you really want to consider that as anything because it wasn't a real fight) but I think people go overboard talking about Greb sometimes.