Atk Tactic?

attack tactic only works on mixed teams. an all infantry team wouldn't be able to use it

if you have a mixed emblem that's something like 2 infantry and 2 cavalry, you can use it there. there are guides on how the skill works in case you're confused

Your Nowi has 56 Atk? Why stack Atk on Nowi?

If you can't find a unit with a different movement type, then Atk Tactic won't work.