(Assumption) In this argument, the arguer recommends that aa. To support this recommendation, the argument cites that bb. Moreover, the arguer points out that cc. However, the recommendation relies on a series of unsubstantiated assumptions, which render it unconvincing as it stands.
In sum, the recommendation relies on certain doubtful assumptions that render it unconvincing as it stands. To bolster the argument, the author must provide clear evidence concerning aa. To better assess the argument, he or she would have to demonstrate that bb.

(Evidence) In this argument, the arguer recommends that aa. To support this recommendation, the arguer cites that bb. Moreover, the arguer points out that cc. Close scrutiny of each piece of the evidence, however, reveals that none of them lend credible support to the recommendation.
After the careful analysis above, it is fair enough to conclude that the author lacks both detailed evidence as well as precise reasoning to make a sound argument. To bolster the argument, the author must provide clear evidence concerning aa. To better assess the argument, he or she would have to demonstrate that bb.

(Question) In this argument, the arguer recommends that aa. To support this recommendation, the arguer cites that bb. Moreover, the arguer points out that cc. However, this argument contains several unanswered questions, which render it unconvincing in several aspects.
In summary, the arguer fails to provide satisfactory answers to several critical questions, rendering the argument unpersuasive. To bolster the argument, the author must provide clear evidence concerning aa. To better assess the argument, he or she would have to demonstrate that bb.

(AE) In this argument, the arguer recommends that aa. To support this recommendation, the arguer cites that bb. Moreover, the arguer points out that cc. At first glance, this argument appears to be somewhat convincing, but further reflection reveals that other possible explanations can also result in dd.
In summary, the author should consider and rule out all other possibilities before making the final conclusion. To bolster the argument, the author must provide clear evidence concerning aa. To better assess the argument, he or she would have to demonstrate that bb.