Safer is Better
You can upgrade each soldier's ATTRIBUTES (Hit Points, Damage, Counter-attack) at the Armor Barracks, for enhanced efficiency in combat. The more units you have, the better the upgrades will work for you. Just so you know, upgrades are researched individually for each type of unit.
You can also add an defensive bonuses to your troops/fleet by upgrading the Ground Batteries and the Wraith Pylon. The batteries give 1% Counter-attack bonus per level, improving that specific attribute of all your units, while the Wraith Pylon will add 1% Hit Points bonus per level. Each structure has 30 upgrades, providing a +30% specific bonus at their maximum level.
I definitely feel safer now
Take me back to Barracks