Idk, I'd go with miners or swords, they're both fundamental units in this game, so you can upgrade them early on. Also, miners are essential if you wanna keep up with the economy if you fight with hard battles while swords are gold cost efficiency yet useful early in the game, health doesnt matter that much cuz if you're careful enough while controlling them, you're fine. Spearton is ehh, kinda optional I guess? I'd rather save it for witch's minions.