title: Merging data using smartbind
body: <p>I have 2 data tables, one with:     </p>
  
  <pre><code>    X1          X2          X3          X4
  1   ClaimIDs    ClaimIDs    ClaimIDs    ClaimIDs
  2   427         419         399         399 
  </code></pre>
  
  <p>and another with </p>
  
  <pre><code>    row.names   X1  X2  X3  X4
  1   3852        0   0   0   20
  2   3853        0   0   0   8
  3   3854        0   0   0   10
  </code></pre>
  
  <p>I would like to make it so that it looks like this:</p>
  
  <pre><code>    row.names   X1          X2          X3          X4
  1   NA          ClaimIDs    ClaimIDs    ClaimIDs    ClaimIDs
  2   NA          427         419         399         399 
  3   3852        0           0           0           20
  4   3853        0           0           0           8
  5   3854        0           0           0           10
  </code></pre>
  
  <p>I have tried everything from r and c bind to smartbind, even to using a listing variable.  It always either outputs with too many columns filled with NAs or does not add in the 3852, 3853, 3854 into the right spots.  Any help is greatly appreciated!  I can provide any code that is needed to solve this.  </p>