The thing about Burnside was that Fredericksburg was not his only mess up. He was late getting started at Antietam and insisted on sending his troops over a sighted in bridge or the creek when it was fordable elsewhere. I think a company or two of sharpshooters held off several regiments there. Then, of course, there was the Crater, although on that one, Meade (I think) and Burnside's superiors messed Burnside up because they did not think the plan could possibly work, so they pulled his best troops. I forget Spotsylvania Courthouse - I know he was there and don't remember a big mess up.