Bandit Camps

[Shooterman56]

I would like to create a system of creep spawning buildings wherein players can create buildings that spawn groups of creeps (friendly to the player only) and have them rally at a certain point on the map.

EG 'Every 30 seconds 'Bandit Camp' spawns X number of bandits at location of 'Bandit Camp', and commands them to go to the rally point set by the player'

• Is there any material difference between creating the units as a summoned unit, with a certain amount of time allotted for their life vs. a trigger to remove them after a certain time? To avoid overpopulating the map with units.
  
• How can i redirect any bounty (or pillage income) made from killing units to the player that controls the creep building?
• My map has 10 player slots, 2 npc controlled teams, neutral victim, and neutral hostile. Would I have to create the units as a unique unused player slot for each player(to avoid different players units from being friendly with one another) ? In most scenarios only 3-4 players would be building these camps due to a separate subclass system that limits who can build these units.

Upgrades
The creep spawning building would have the ability to upgrade into 3 superior types of camps, with the ability to upgrade laterally to the other 2 after purchasing the first upgrade.

• What would be the most efficient way to structure the different unit spawning triggers? Ideally I would be using 3 similar triggers to the base trigger. Seems that having the triggers for the 3 upgraded camps initially turned off, although I'm not sure how much this helps with performance.

Thanks for your time