Given that at least 75 people were violently killed in 2016 on church/faith-based property in the U.S., should churches have security teams?

This is not a new thing, SSG William Jones. African-American churches were bombed and/or immolated for decades.

Also, some may remember Rev Billy Joe being sucker punched during his worship service some years ago:

Check out this video on YouTube:

http://youtu.be/BnzlJEH30vw

Yes, fortunately, yes that is where we are...

To put it bluntly, each person is responsible for their own security. There is no one closer than oneself when danger shows. Stop relying on others to protect you, even the Supreme Court has ruled the police has no mandate to protect the citizens.
Did your ancestors rely on the Calvary to protect them or did they rely upon themselves?