So, unless there is a specific reason (natural disaster, uncontrollable riots, etc.) there’s no benefit to sending military troops to the scene.

I think that's wrong. And I think it's why Democrats get pwned on "mantaining order" issues.

If I went to the Lincoln Memorial and saw a group of teenagers climbing on the statue of Lincoln and riding their mountain bikes down the stairs, it would make me feel uncomfortable and less safe there. Because that's a pretty good indicator that something is going wrong. Public order is not being maintained, and it's being broken in a pretty significant way. No, it's not rioting; no, it's not looting. But what I just described are also things that are just not supposed to happen in a place where public order is being properly maintained. I might know intellectually that this doesn't mean there's a material increase in my being the victim of a violent crime, but we all use heuristics to gauge the safety/protection of our surroundings.

If there's troops there, there aren't going to be kids messing around on the statue or riding their bikes down the stairs. You won't have a breach of public order.

This is why Democrats run the risk of getting baited into a politically damaging response to all this. If people feel like cities are less safe (for the reasons I mentioned upthread), it is political suicide to try to convince them that they're wrong for feeling that way.