Best chance for 1 on 1 is away from pit road (Gordon Burton push)...or you need to be lightning fast creative getting to the other driver before anyone gets there (Bowyer Newman flurry)...Kenseth running up behind BK at the motorhome. There's ways to get it in if you really want to...problem is usually 1 of them doesn't really want to fight or they take their sweet ass time waiting too long.
Crew members should never being initiating a take down on a driver, seriously wtf at that horsecollar take down of Hamlin, the guy is lucky he didn't do any damage to him. It's driver on driver, or crew on crew if they want to get involved, there's a large difference between stepping in front to prevent an altercation or pulling someone off of someone getting their head smashed in. God forbid your driver handles his business and gets punched in the nose, the risk of more serious injury type of damage is when it becomes a larger scuffle with the crew involved. So with that, I do agree, the crew should not be immediately jumping in because they think this is their moment.
Personally, I'd rather see great racing with it settled on the track.