My tactic is
1. I will try to deal dmg to this one ranged guy
1.1 if i miss than i cant CC him and recive tons of dmg so my mage should be ready to heal and buff me some dodge and deal some dmg to increase my overall CC chances.
1.2. if i not miss, than my mage should not heal me but slowdown that melee enemy who is very close and TP him away
2. if 1.2 is true then i will try to CC that guy
2.1 if i miss with CC then i should prepare my resurecting scroll, but i have a good chances so ill take that risk
2.2 if i not miss with CC so all party members should focus that melee guy
This works in games without RNG, too. An example from Invisible Inc.:
You see a guard in a room
You can kill him, but this requires expensive ammunition and the alert level of the mission will increase. The money for the expensive ammunition could be needed later in the mission to upgrade your gear or the increased alert level could make the mission more difficult if other guards try to locate your characters.
You can stun him for a few turns, but the guards will try to locate your characters as soon as he wakes up.
You can stun him permanently, but this requires that one character of your team stays close to the guard for the rest of the mission.
You can try to avoid him, but that could be dangerous if nearby guards try to locate your characters later in the mission.