Wow, it is excrutiatingly hard to get 5 people to ult at the same time. First you have to tell your team "I'm gonna ult, you stun when I ult."
Then you gotta get them to group "group guys" "stop farming top teemo" "graves gtfo over here" "alistar don't get caught warding"
Then you gotta get them to teamfight "Push" or "def", or "gank em"
Then finally you ping a couple of times (You can't ping more than a few times cuz they'll get pissed off.
Then FINALLY you say "Next wave I ult"
THEN YOU PRESS 'R' AND IF YOU'RE REALLY, REALLY, LUCKY, YOU'LL BE ABLE TO GET A GOOD COMBO OFF.