This assumes that the Valley Campaign plays out the same way with Cross Keys being the penultimate battle. Let's back up a step. It is not hard to make the argument that anyone other than Fremont would have closed the trap on Stonewall at Strasburg as he was consolidating and retreating up the Valley to Cross Keys and Port Republic. My money would be on Rosecrans.
I think it’s a hard argument to make for anyone and a really hard argument to make for Rosecrans. Unless given extended time to prepare and plan, Rosecrans was not known for quickness of movement
Maybe you can explain how the results would have been different as I dont see it