I actually highly dis agree with that. Also you can be unpredictable /w a team as well.
The only time you become a target fro Rifle Nades Flamers ans mortars is when your to close together. Team work isnt just sticking within 5 meters of your mate and shooting at his targets. It can mean alot more things.
I hate to admit but alot of people dont know how to work as a team effectively. I dont think thats the job of the server admins either. But most people just dont even want to try and thats what annoys me alot. You don't always need instant communication a good briefing can probably do the job as-well.