So, to start off, have you made a new "soldier" class for your soldier models in the faction file? If you haven't, a simple way of doing that is copying the first block of soldier code (the "default" named one) and just pasting it below the "medic" and renaming it. Change the skins and that should be the basic part down.

For the call-in to get them, the only way currently of getting them on the battlefield is via a paradrop (or just plain spawning them, if you lower the spawn height). So copy the paradrop call-in and rename it, then open up the file and remember to edit the key to match the file name. Change the "round_instances" to however many you want to spawn (I think you wanted 4, 8, and 16) and change the "instance_key" to the name of the new soldier you created in the faction file earlier. Add this call to the all_calls.xml and the faction's call list and you should be good.