I see a lot of assumptions going on about what this Klingon sentence — not the English translation — means.
Let's check that by first noting that the comparative/superlative literally means A's Q is many; B's Q is few. It doesn't follow basic sentence syntax, but that's okay: we're told that comparatives and superlatives have their own construction.
reH latlh qabDaq qul tuj law' Hoch tuj puS
So what is the scope of reH? What is the scope of latlh qabDaq?
We know that latlh qabDaq cannot be attached to qul because a type 5 noun suffix cannot be anywhere in a noun-noun construction but at the end.
We can suppose both reH and latlh qabDaq belong to the space before sentences: [reH] [latlh qabDaq] [qul tuj law' Hoch tuj puS]. This would mean Fire's hot is many, and all else's hot is few; this is true always and on another's face.
We might also suppose that the reH remains before the main sentence but that latlh qabDaq modifies something else, and qul just gets in the way because of the odd syntax. It might be attached to tuj: fire's hot-on-another's-face is many, and all else's hot is few; this is always true. Or it might be attached to law': fire's hot is many on-another's-face, and all else's hot is few; this is always true.
Given the odd syntax of the comparative/superlative, the unexplained nature of observed modifiers outside of that construction, the fairly non-literal nature of the proverb (What the heck does it MEAN that the fire is hotter on someone else's face? What fire? Hotter than what? Hotter than another fire?), and the very fact that Klingon proverbs are prone to containing grammatical exceptions, I don't see how we can draw any solid conclusions.