I'm not quite sure I understand the issue - what you describe is the SAME in Pages and in Numbers.
Create a table in [Numbers or Pages]
Enter 1 in the top-left cell
Enter 2 in the cell below
Click and drag to select the two cells
Drag the handle down to fill the column
--> the column fills with sequential numbers
Delete a random row in the middle of the table
--> cells below move up, numbers remain the same (with a missing number in the middle)
This is the same in Numbers and in Pages
Furthermore, in both applications, I can simply re-select the top two cells in the column and drag down again to resequence the numbers.
If you want the cells to automatically renumber as rows are deleted (in both Numbers and Pages), then use a Formula.
In the above example, set the top cell (A1) to 1
In the cell below, enter: =A1+1
this cell is now a dynamic formula, not a static value.
Drag cell A2 down the column and now the cells will fill with formulas that increment based on the cell above.
Now when you delete a row (again, the same in Numbers and Page), the following rows will automatically adjust.
So it sounds like your solution is to use numbers that describe what you want the cells to show, rather that setting them to fixed values.