Not really. I'm suggesting that Walsh would be running next to Koula and Saab at 20-30m mark at best, not in front of them. Walsh has great anticipation and is already at top speed when he gets the ball, so it looks like he is flying but if you put him on a track, he wouldn't be visibly in front of Koula and Saab at any point. He'd be next to them at best and be 30m behind them at the end of the 100m. You can't judge a players speed by how fast it looks like they're running.
Saab looks effortless and takes giant strides, as does the Hammer. Then you get the guys with the shorter, stockier legs and they look quicker but actually aren't. Geoff Toovey is a great example. He had an excellent turn of speed and would burst through holes but he was never considered a 'speedster'. The same goes for Dylan Walker (before he had the horrible ankle injury) and Billy Slater. Speaking of Walker, he scored a brilliant try against the Roosters at the SFS in 2017, running off a ball from Bryan Kelly. He burst through at a million miles, just like Reece Walsh does, and big Dan Tupou (who was chasing from well behind) looked like he was running in quick sand and actually almost caught Walker, who looked like he was flying.
Anyway, I am not trying to convince you of my opinion, because you'll stick to your guns regardless, but I thought I would throw my 2 cents worth in as food for thought for the benefit of other readers.