I have just beaten the game, after around 5 times that I reached 1-2 / 1-3 and died.
Something I'd say might be a bit broken are shield-giving units in huge groups.
Like, all I needed was to find a square free from aggro and run around for 10 seconds, so that my shield wolves could armor up my entire undead army.
Like, I probably halved my frames at a certain point, but I stomped through with no issues.
Probably a way to nerf it would be to reduce the amount of shields it could give.
Maybe something like " can only shield up X units with each proc" or something like that.
Or, for example " X units + 1 for every other Shield Wolf".
Still, it's a strategy highly dependent on both the presence of one of those units that give you permanent monsters and, most importantly, on the presence of a safe square.
Honestly, this is the reason why I had previously noticed the presence of "faulty" range.
Still, I hope you have a great day!
Bye!