As you've aptly noted, Sherman was a very effective strategist and that is where his primary focus would have been of course on larger strategy and ensuring the North's offensive Total War strategy was maintained, keeping in stead with Lincoln's war goals (The concept of Total War is of course still open to debate, however Edward Hagerman makes a rather convincing case in Union Generalship, Political Leadership, and Total War Strategy).

Thus he wouldn't of necessarily have had a major involvement with tactics. However John K. Mahan highlights that Sherman did play a role in the development of new irregular skirmishing tactics in his article on 'Civil War Infantry Assault Tactics', "If anyone saw this at the time it was General Sherman, who in some cases used a line or lines of skirmishers instead of the battle line of two ranks.3 Obviously skirmish formations thrust added responsibility upon junior officers." I have struggled to find any other sources on Sherman's tactics. However, the effect of using lines of skirmishers should not be underrated, it was definitely another step in the development of infantry tactics towards their modern form. Afterall, the Civil War can be seen as a testing ground for adapting tactics to new technology, as English and Gudmundsson write in 'On Infantry', "By far the most extensive "civilised" war of this period [The American Civil War], its many battles and engagements were fought in an almost infinite variety of ways that ranged from primitive to the nearly modern."

Hope this helps!

Sources CIVIL WAR INFANTRY ASSAULT TACTICS in Military Affairs, Vol. 25, No. 2, Civil War Issue (Summer, 1961), pp. 57-68 - John K. Mahon

Union Generalship, Political Leadership, and Total War Strategy in On the Road to Total War - Edward Hagerman

On Infantry - John A. English and Bruce I. Gudmundsson