This little mission, which I did not take the time to polish up, has within it several scripts. Most of which I did not make myself, but proper credit is given in the documentation.
The mission features a small squad of west JAM_Units(the ones from BAS's blackhawk pack, yes you need to have them to use this). Your squad is walking along and it is attacked by 5 enemy units. Once there are only two enemy units left, 4 or 5 more spawn a little bit away from you position. This allows for extended firefights, but also will not lag your cpu down by having 80+ units on the battlefield at one time. The way it is set up now, the firefight will last forever, however, if one were to add a counter to the script the mission could last as long as you wanted it to, and discontinue the respawning at a certain time.
I must take the time now to give a bit of credit to CrashnBurn, we worked on respawning units roughly a year ago. Apperently he created a script using the creatunit command, which is a simpler way of doing things, sort of.
I am sure you guys can come up with some cool uses for this script. There are infinite possibilities with this. It would not be difficult to create any kind of unit on the fly.