I can buy part, but not quite all of that. Remember please Sir, that Forrest was only about thirty miles from his home until 1834. He had also led his Escort through this area and had fought at Franklin and Brentwood previously as well as Thompson Station. It was Forrest who had done his best to evacuate Confederate supplies from Nashville in advance of Grant's arrival in 1862. He was no rookie at this point in time. Forrest had been skirmishing with components of Hatch's and Croxton's cavalry all the way from Florence. They had met at the Harpeth on the 29th with not too satisfying results from Forrest's perspective. He could have crossed the Harpeth to the east and approached Franklin from the east. Given enough men, which Hood refused, he could well have diverted Schofield's attention from Columbia Pike. How strong Wilson, Hatch, Croxton, Hammond and the US 4th cavalry could have been, we'll never know. I really don't want to. My gg grandpa was a farrier tending to those horses. Forrest would and did have several more opportunities to train these yankee horsemen during the Confederate retreat in the week and a half following Nashville.
Schofield had the luxury of using the bridge on the Nashville/Franklin Pike north of town for moving his equipment as you state. The vast majority of his men, aside from the mentioned cavalry, were concentrated there along that ditch in south Franklin, waiting for Hood's ill-advised approach. If Forrest and Cleburne advised me that this was a bad idea, I'd have given that some consideration. Hood was not that kind of general, unfortunately for the AOT.