Scipio and Elise
These two are so close in stats that their basically the same General. Miles above the rest of the Ground Generals, you'll find these two certified BEASTS. Unfortunately them being only available through packs leaves a lot to be desired for the non-spenders.
Trajan and Epaminondas
Trajan is the only viable Ground General in the tavern. But he also makes a halfway decent Wall General when needed and works well for reinforcing due to the non-qualifying wording of his Special Skill.
Epaminodas is slightly better than Trajan but not available for free. If you get him instead of Scipio or Elise from a packs, you should probably cry for a bit; then start working on him.