There was an excellent article in the April 2000 (Vol 3, No.4) North/South magazine that did just that. The name of the article was "Formidable Only in Flight: Casualties, Attrition, & Morale in Georgia" by Steve Newton. Steve does an excellent job of breaking down battlefield casualties, missing soldiers, losses to sickness, & readmissions amongst both Federal & Confederate armies. "Under Johnston's leadership the average daily casualty rate was 195 casualties per day for 73 days; under Hood this average increased to 375 casualties per day for 47 days. Although daily averages only show general trends over weeks & months, it is evident that the Army of Tennessee suffered signficantly more casualties over a much shorter period under Hood than Johnston."These numbers need more scrutiny; one may have to repair to eBay to get a copy of the issue in question.
Where things break down for the Confederates is in the hospital & recovery phase. The Federals were MUCH better at getting men back to the battlefield than their Confederate counterparts. For the Confederates, the really telling part is not casualties TAKEN, but in casualties INFLICTED. While Johnston in 73 days of combat generates nearly the casualties that Hood does in 47, the Yanks take 20,000 LESS casualties due to the battlefield & sickness under Hood than Johnston. Hood takes greater casualties faster & inflicts less damage than Johnston.
Atlanta's numbers (cont.)
Andrew Wagenhoffer wrote in to mention that Steve Newton wrote about Johnston's retreat numbers in North & South ages ago. "I found some talk on the article on the Armchair General." Here's a snip from that board: