I just finished a short article about the grounds for contested divorce in Tennessee. Since divorce law varies state by state, but not county by county, the grounds are the same no matter where in Tennessee you are getting divorced. Sometimes there is variance on interpretation depending on which county your divorce is in, but the variance is limited by caselaw. Although Tennessee is notorious about not having caselaw in a variety of areas, the sheer numbers involved in domestic have resulted in a decent amount of appellant and supreme court opinions. This means that there is not as much wiggle room in interpretation on a county by county basis between the counties on the issue of grounds as there may be with other statutes or other areas of family law such as parenting plans and alimony allocations. So while strategy on a Davidson County divorce will differ from a Sumner County divorce, the grounds available to the attorney will be the same.
You can read the different grounds for divorce in Tennessee under T.C.A. § 36–4–101 here: http://contesteddivorcelawyernashville.com/contested-divorce/grounds-for-contested-divorce/