I get the feeling that "good" ranges from good two turners such as the crusader and the ram to good three turners like the elemental, sandworm and catapult. "Normal" ranges from normal one turners to normal two turners. "Poor" has very few units. "Powerful" can be both archon and grand archon.
Would it be better to add a setting or two? Example: crusader could be "good", pegasi "good+", dragon "powerful" - so there would be one setting for each of the same type.
Maybe add a list to the "detailed settings-menu" that says which units belong to which settings? Or just use the gold range as name. "200-400" = "normal" Or "normal (200-400)".