Expert Fighter Formation
Once you have done well with your formations setup you should notice an increase in both might and damage. However, you will notice that if you use five fighter heroes and all fighters in your troop formation, that the highest level fighter hero has his or her tactical skill disabled during a battle.
There doesn’t seem to be a really good answer for why this happens, either its a bug that has never been corrected, or intentional and the developers don’t intend on explaining why this is the case.
Let me clear, you do not need to have all your heroes tactical skills available to be effective in a battle. The original formation I have detailed under Fighters will work just fine. Troop skills will work no matter the situation, however to get all of your heroes using their tactical skills you actually have to do something special, and contradictory to building a specific type like fighters.
Here you can see above that I have a troop size of 245,700 which allows me to, if I want include all fighters, and fighter heroes. Unfortunately, if I do this then my strongest hero, usually Ulrick has his tactical skill disabled. But I do not want that so instead, I have included Requiem in my lineup as a replacement for Seo-Yun.
In truth Seo-Yun’s Troop skill grants a higher Fighter ATK bonus at +5 of 50% You can see this in the image on the left. But Seo-Yun is only a four star hero so she cannot enhanced further than +5, nor red-starred.
However, Requiem whose Troop skill is lower at only 40% at +5 red-starred, has the advantage of her being enhanced further than Seo-Yun, which at red-starred +6 her Troop skill grants 51.2% Troop ATK bonus which exceeds that of Seo-Yun.
However, getting the addition 500% Troop ATK tactical skill activated during a battle more than makes up for the 11.2% you lose swapping heroes at these levels.
This is not a limitation that requires you choose a Troop based Troop skills hero like Requiem, you can use any other type of hero other than fighter and it will work, however there will be a larger reduction in might depending on which hero you choose.
For example when you use Requiem (Shooter) or Mars (Rider) these heroes grant their troop skill bonuses to all troop types, thus fighters are included, as well as riders, shooter and even vehicles.
If you were to include a hero whose Troop skill only benefited a specific type like Ephraim whose skills only grant stats to Shooters, then your fighters would get zero stat bonuses from him being in the lineup, so the advantage of using a hero that grants all troops a bonus—albeit less than a normal type hero—is that any number is higher than zero, so even if Requiem only granted a 20% troop bonus, that means your fighters would get 20%, as opposed to Ephraim being included and giving your fighters 0% bonus.
That is why this works best if you use a hero whose troop skills benefit everyone as opposed to a specific type.
However, there is another caveat.
You must include a number of troops of the same type as the hero type you are using for this purpose. In this case I am using Requiem, so I need to include some Shooters in my troop lineup for her to activate her tactical skill.
To be safe I recommend including 1000 of the troop type of that hero, in this case Shooters. If the number is too small, they may get killed before she has a chance to activate her tactical skill. If all the troops of a specific type die, then that hero can no longer activate their tactical skill, which is why I choose 1000.
It’s big enough to allow her to activate her skills without worrying the shooters will just be wiped out, but its small enough that the primary might is coming from your fighters, and fighter type heroes.
(For this to work properly my recommendation for this lineup includes your four strongest fighter type heroes and someone like Requiem, Mars, or Marlowe. However, do not use Meyers or Tomoyo as these two are fighters and therefore will not activate their tactical skills.)