“Khālidun mujtahidun wa-Saʿīdun amīnun” coordinates two declarative clauses. When they are compatible in communicative function and meaning, the conjunction can be rhetorically suitable.
Yet proximity alone does not establish the need for wa. The semantic and grammatical relationship must be identified. Where the second sentence explains or answers the first so closely that simple coordination is less appropriate, separation may be preferable. Sound analysis considers the relation between clauses, not whether a conjunction merely sounds pleasant.