Using Fire emblem tactics in a game like this ends in disaster, since they don't teach much about first strike advantage, using meatshields to protect your important units and aim to weaken many enemies instead of aiming for kills.
If you have a 10 hp cav with an enemy cav and you got the option to attack a 3 hp or a 10 hp cav, you rather want to weaken the 10 hp cav so it won't hit you for massive dmg on their turn, instead you leave two enemies at low hp, who deal less dmg combined than a full hp one and also both suffer more counterdmg than they have dealt.
Because "your hp = your dmg" you not only wanna lower the hp of your enemies to lessen their dmg, but also keep your own important units as full as possible.
Using villagers as meatshields is a great way to prevent enemies from hitting your better units, so you can retaliate back with them at their full strenght.
Being an Advance Wars veteran with some Wargroove experience, I did get the feel of the game after putting my Fire emblem experience aside.
I was able to breeze through the game on hard mode, no map really gave me trouble.