Print 1 to 15, using different printers
Pyth + ///, 15 bytes - 10 = 5
pPt`S15&quot;, STOP!

This prints 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, STOP! in Pyth, by taking range(1,15+1) and stripping off the start and end brackets, and printing it immediately followed by &quot;, STOP!&quot;.
The next fourteen programs are in ///, which directly outputs all programs that don't contain / or \. So the second program
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

gives 2 and the third program 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15. The penultimate program, 15, STOP!, prints 15, STOP!, so the last program is just STOP!.