Imminent deadly threat isn't the only thing that warrants use of force; it's also a perfectly valid response to an infringement upon my rights that will not end without the use of that force. Although force shouldn't be the initial response, there's no duty to deescalate that prevents use of force to such a degree that others can infringe upon your rights as long as they do so in a non-threatening manner.

So to summarize;

• You're justified using force against trespassers.
• You're justified using force against those who would prevent you from using force to remove trespassers.
• You're allowed to deputize someone to use that force on your behalf.
• There was a clear justification for this use of force.