Two stars signify a Union Major General - the Confederate Army did not have a star insignia for their general officer ranks - all of them wore three stars with a wreath around it - except for Lee and he wore a Colonels rank - three stars only (see pictures below) - the whole war. I can not find a source on sashes other than color (US OR CSA )- no one indicates that there were any rank indications on a sword sash. But then Generals, we know could, do any thing. I do not know where the Lt. Gen. statement came from but it does not apply to the CSA. Grant by the way was the only Union Lt. General, so if it was a Lt. General's (would have to have 3 stars) it would have to be Grants. There was a higher rank in the CSA (General)

Forrest did capture a Major General Washburn's sword and uniform on the raid on Memphis in August of 1864 but accounts say he returned same. Maybe he kept the sash.

All ranks of Confederate generals received the same base pay because the Confederate army regulations recognized only one grade above colonel. Generals holding different commands, however, earned additional allowances for additional rations, fodder, fuel, quarters, and seniority. In addition, generals commanding an army in the field received $100. Therefore, in 1864 Robert E. Lee's monthly salary totaled $604 a month. This amount included $301 base pay, $108 rations (for 12 rations a day), $32 fodder allowance (for four horse rations a day), $63 seniority pay (for $9 per month for each five years in the service, including those years he served in the United States Army), and $100 as an army commander.

In the Confederate Army, by 1862 there were four grades of general: brigadier, major, lieutenant and full general. All wore the same insignia making it impossible to identify a general´s rank by his uniform.