The revised expression must be judged by whether it is more eloquent, not merely longer, more ornamented or less familiar. Eloquence depends upon fitness to context and effective communication.
A recasting that is more coherent, concise or forceful in its new setting may have recognizable merit. An alteration that damages the structure or confuses the sense is not an improvement.
The origin of an expression and its artistic success are different questions. A borrowed idea can be expressed more effectively without thereby becoming an independently invented idea.