User blog comment:Mescolinares/TRUE power of the “Horn of the Goblin General”./@comment-67.160.206.30-20160114013805/@comment-27557332-20160114032015

Most likely

1. # of opponents or level of danger. (It's likely that the user has to have a rough idea of how large the opposing force is.) The volume she used the Horn with may also affect this. The first Horn was barely blown; it's likely that only those in the same room heard it. The second time, she gave it all she had. The Kingdom Forces back in Carne probably heard it even though she was well away from the village. (This would make sense on how the Summons appear... they would have to appear within earshot of the Horn. The more the sound carries, the larger the affected area. Which also explains how the Assassin Unit and such got through Kingdom Lines... If the Horn is tactical in any way, the Summons would probably appear in the best tactical position without compromising surprise.)

2. Some kind of troop controller job. My guess is at 'Sergeant' she'd only get a 'Patrol'... which is 12-24; Consistent with what she got from the 1st Horn. As a 'Commander' (Which I'm assuming is actually supposed to be 'Company Commander.') it would be a 80-250 man Company. 'General' at the lowest rank would get a full brigade, which is 3000-5000 excluding command staff.

3. The 3rd requirement is probably the Unit Mix. It's probably based on the combination of jobs Enri has available, which would explain why she got a Mixed Unit Strike Force instead of a homogenous unit. (Example: A US WW2 Tank Brigade were usually 3 Regiments of Tanks and 1 Regiment of Support Infantry. What Enri ended up with is closer to a modern Stryker Battalion rather than the traditional Brigade.)