 Although there exist some partial overviews of them, a recent survey is a necessity as the growing number of the methods may cause  uncertainty in practice.
<fluency>  Although there exist some partial overviews of them, a recent survey is a necessity as the growing number of the methods may cause  uncertainty in practice.
 Although there exist partial overviews of them, a recent survey is a necessity as the growing number of the methods may cause uncertainty in practice.