Late to the party here, but I would say: go for it. There is no reason why nouniness of adjectives would prevent the two word classes from working in different ways. For example big > bigger, but kill > killer; -er goes for both comparatives on adjectives and agentive nominalizations on verbs. This sort of thing happens in nature, and it's normal and common for linguists to use such differences as tests for a root's default syntactic category.