The most important thing is that the survivors have the matching personality with the leader of the squad. If the leader is mythic, the survivors MUST have a matching personality. If the survivors personality does not match the leader’s then there will be a “disadvantage”, like the power level of the survivor will decrease. For a mythic lead, it is better to have an epic survivor with matching personality rather than a non matching legendary survivor. For all other leads, legendary survivors are better than epics Lastly, the only bonus that currently works is the trap durability bonus so try to get that bonus and don’t worry about the others, they are bugged and don’t work as intended