Right now we can use the '/scoreboard teams' to divide ourselves into groups and make the armies fight eachother.

My request is for a way to have teams and have NPC's still be neutral to players and NPC's of another team.

Maybe a command could be added for this:
/war teamname => start aggression against NPC's and players of that team

/peace teamname => will send a message to a teammember of that team to reply with /peace accept teamname or /peace decline teamname

/ally teamname => war againgst any of the allied teams cause both teams to go to war

Since I'm no good at coding I have no idea wether this is a easy option or not