Hi Ryan,

Yes, it is possible to combine the two arrays. Here's how you can do it:

1. First, you need to combine the two arrays into one. You can do this by using the CONCATENATE function. For example, if your first array is in cells A1:A10 and your second array is in cells A11:A20, you can combine them into one array in cell B1 by entering the following formula:
   
   
   Formula:

   =CONCATENATE(A1:A10,A11:A20) 

2. Once you have combined the two arrays, you can use the same formula you used to eliminate duplicates:
   
   
   Formula:

   =IF(ISERR(SMALL(IF(MATCH($B$1:$B$20,$B$1:$B$20,0)=ROW(INDIRECT("1:"&ROWS($B$1:$B$20))),MATCH($B$1:$B$20,$B$1:$B$20,0)),ROWS($1:1))),"",INDEX($B$1:$B$20,SMALL(IF(MATCH($B$1:$B$20,$B$1:$B$20,0)=ROW(INDIRECT("1:"&ROWS($B$1:$B$20))),MATCH($B$1:$B$20,$B$1:$B$20,0)),ROWS($1:1)))) 

3. This formula will eliminate duplicates from the combined array.
   

Regarding your concern about the workbook slowing down, using array formulas can sometimes slow down a workbook, especially if you have a large amount of data. However, if you have a relatively small amount of data, it should not be a problem. If you do notice that the workbook is slowing down, you can try using other methods to eliminate duplicates, such as using the Remove Duplicates feature in Excel.