The was no reason to rush to action here. The clones could have been removed to the Enterprise, where they would have matured in safety.
Well, that in itself constitutes a reason. By immediately killing the clones before they became citizens, Riker and Pulaski could probably preempt the legal action that would come to play with a fully matured clone. I mean, if "A Man Alone" describes UFP rather than Bajoran law, then clones attain rights only hat the point where they reach consciousness, which seems to coincide with them ripening biologically into fully grown adults.