The fact that Cryo just sensed the fact that FNS is baiting for another teammate shows how important ranked games are even for pro matches. Cryo is a ranked demon and he definitely has had this situation multiple times.
A team can only scrim for a limited time with actually good quality teams.
You need to be in different situations many times to be that good. Ranked might not be good for set plays but it helps develop your individual play potential. You cannot face every 1v3, 1v2 situation in scrims. You play ranked much more than you do scrims. These plays like baiting for your teammates is quite common ascendant and above.
The more you face these situations the lower your chances of being outplayed.
Also I am not sure what exact moment are you talking about where he should have swung.