You don't run 100m in 10.58 if you are slow to get going. Walsh never won any kind of junior sprint trophies. It's deceptive. He has great acceleration (gets to top speed quickly) but I have seen him gas and be run down from behind by lesser names than Koula. He gasses very quickly.Over 20 - 25m, no chance. Walsh is quicker imo.
25 to 50 probably Koula
50 - 100 Saab baby
Walsh might go neck and neck over 20-30m and then be left for dead.