1.The arguer may be right about …, but he seems to neglect (fail) to mention (take into account) that fact that… 
   2.As opposed to (Contrary to) widely (commonly/generally) held (accepted) belief (ideas/views), I believe (argue that… 
   3.Although many people believe that …, I doubt (wonder) whether the argument bears much analysis (close examination). 
   4.The advantages of B outweigh any benefit we gained from (carry more weight than those of / are much greater than) A. 
   5.Although it is commonly (widely / generally) held (felt / accepted / agreed) that …, it is unlikely to be true that… 
   6.There is an element of truth in this argument (statement), but it ignores a deeper and more basic (important / essential) fact (reason) that… 
  7.It is true that (True, / To be sure, / Admittedly,)…, but this is not to say (it is unlikely / it doesn’t follow / it doesn’t mean / it won’t be the case) that…    8.The main (obvious / great) problem (flaw / drawback) with (in) this argument (view / remark) is that it is ignorant of (blind to) the basic (bare) fact that … 
   9.It would be possible (natural / reasonable) to think (believe / take the view) that…, but it would be absurd (wrong) to claim (argue) that … 
   10.In all the discussion and debate over…, one important (basic) fact is generally overlooked (neglected). 
   11.There is absolutely (in fact) no (every) reason for us to believe (accept / resist / reject) that… 
   12.Logical (Valid / Sound) as this argument and I wholeheartedly agree with it, it appears insignificant (absurd) when … is taken into consideration (account). 
   13.To assume (suggest) that … is far from being proved (to miss the point). 
   14.A close (careful) inspection (examination / scrutiny) of this argument would reveal how flimsy (groundless / fallacious) it is. 
   15.On the surface (At first thought), it (this) may seem a sound (an attractive) suggestion (solution / idea), but careful weighing on the mind (on closer analysis / on second thought), we find that… 
   16.Too much emphasis placed on (attention paid to / importance attached to) … may obscure (overlook / neglect) other facts… 
   17.The danger (problem / fact / truth / point) is that… 
   18.What the arguer fails to understand (consider /mention) is that… 
   19.We don’t have to look very far to see (find out) the truth (validity) of this argument (proposition). 
   20.However just (logical / sound / valid) this argument may be, it only skims the surface of the problem.