We are discussing apples and oranges. Belton Cooper was talking about the Shermans knocked out by Panzer Fausts, not about the shell from an 88mm.
It seems that there are a variety of opinions, e.g. see below from just one page of search. The 88mm comment was referring to the greater diameter of panzershreck (and panzerfaust) compared to bazooka.
Sandbags would do nothing against a pak43 or Flak88 except slow the tank to make a better target????
https://forum.axishistory.com/viewtopic.php?t=153140
Sandbags were a form of external protection against Panzerfausts and Panzerschrecks. The sandbags served more as a morale-booster for the tank crew. There was a downside to the use of sandbags - the extra weight caused excessive strain on engines, increasing demands on maintenance procedures and shortening the life expectancy of various mechanical parts.
Alternately the sandbags but especially boards and such could predetonate the shaped charge allowing the "slug" more time to form and actually increase the penetration. Note that the physics of shaped charges were poorly understood at that time and that most post war shape charges have an extended fuze to allow the charge to detonate just prior to impact for greater penetration.
The main lethality of such munitions comes from the 'spall' formed when the armour is perforated - the wider the hole, the more lethal (but less penetrative) the result. (source "Military Ballistics" - C L Farrar & D W Leeming - Brassey's Battlefield Weapons Systems & Technology, Volume X). The Germans were leaders in the military applications of shaped-charge munitions - first used in the reduction of Fort Eben-Emael in 1940.
I can't remember where I read this, but Gen. Patton became very angry when he saw sandbags on tanks of one of his armored divisions, and ordered their immediate removal. hIS explanation was that the weight decresed fuel consumption, and the bags in themselves provided minimal protection, because unprotected parts of the tank would become a target.
Georgie Patton spent most of his time cruising around the rear in his staff car and posing with his ivory-handed pistols.If I was a Sherman tanker with the choice between a little extra protect with the sandbags and more fuel consumption,I'd pick the sandbags every time. U.S.Army(Retired)
"He spent of his time cruising around the rear in his staff car and posing with his ivory handed (?) pistols"??? Really?? Do you have documentation or a source for that claim?? , U. S. Army (retired)
So, is this the five minute argument or the full half hour (to twelve years....).