personally i am against tags above peoples heads. its 2018 every1 should have a mic already. and whenever you are grouping up with people, 99% of the time you do it with friends. thus you are already communicating with them. so its not that hard to tell them where you are and if you communicate good enough you dont have to jump to let them know its you... i guess you could turn on tags on the map, just so you have a quick overview of where every1 is.
then again, there is a max group limit of 4. So its very unlikely you are gonna get zerged by the famous thai clans ( even tho they gave you alot of free kills )