Just to clarify.

You mean if they had attempted semi static, attrition based warfare earlier then would they have done better?

Because from about the fall of 1863 on almost every major engagement from Atlanta to the Overland, to Petersburg was full of fixed fortifications and impressive field works

As for speculation that is not the purpose of the sub.

But the reason the CSA had to adopt an aggressive defense was simply their underdog status in resources. By sitting back on the defensive they put no pressure on the Union and allowed them to build and his band their already greater resources. The Union could attack more locations then the CSA could defend. So a bold strategy was needed. On a tactical level it could help whoever was the defender, and protect vital rail lines and ports. But as a general rule for the field armies sitting on the defensive was counterproductive for the South.

Sorry, but your submission has been removed because we don't allow hypothetical questions. If possible, please feel free to rephrase the question so that it does not call for such speculation, and resubmit Otherwise, this sort of thing is better suited for /r/HistoryWhatIf.

However, there is an error in your premise! If you care to restate the question along the lines of "How did their utilization in the America-Civil War influence the development of Trench Warfare?" that would be fine, as we actually see their use in the Siege of Petersburg and a few other battles.