Honestly, I too have had some problems with how the resolve/stress mechanic works in the game when taken literally from the game rules. Replicants seem to have been given limited resolve as a way of balancing human PC's vs Replicants in terms of power.
This is fine, but with their resolve pool being so small, it seems that as soon as one of them fires automatic fire and then gets returning fire, they are prone to a break down that makes them completely ineffective in most cases based on the Replicant Critical Stress Effects Table.
The other problem I have with using this table is that it mandates too many overly specific actions if the character is a PC with seemingly no choice. It seems as if the writer wrote a table for all replicants based on just Roy Batty's reactions as an example. We see a lot of his erratic and contradictory reactions in this table but the actions of almost all other replicants in both movies tend to make more tactical sense, unless they never broke from stress.
I intend to nerf the table itself down and leave it more up to the PC's to describe their own stress reactions. Perhaps forgoing the table completely if the player prefers to describe or roleplay their own stress breakdown. I may even reward the best/most appropriate reactions with Humanity points.
For my replicant NPC's, that are broken by stress, I may use the table, unless I have a better idea of a reaction that fits the scene. Especially for major characters. For nameless NPC's I will probably use this version of the table that uses only short descriptions. These reactions in essence match the table in the rules, they just leave it for me to fill in the details I want that fit their motivations and character makeup (if I use it at all). It also prevents giving a nameless NPC meant for cannon fodder, screen time and a scene that matches the death of Roy Batty. After all, we don't need one NPC giving a "I have seen things you people wouldn't believe..." speech and then in the next combat round, his buddy does the same just because they both rolled 5's on the table when broken.
I will also look at what the main stress causes are. For example; if covering fire is the cause, then they may be pinned down where they are at and cannot react or return fire other than to try to get more and better cover. They are not having a nervous breakdown or and existential crisis, but they may simply be unable to move or take action while under such fire... hmm... kinda like what covering fire actually does. (this may also, depending on their combat experience per their back story, determine whether they freak out or not). If some conditions of the stress stop, then perhaps they get an advantage on their Insight roll or the point goes away automatically. GM call.
In all cases though, the stress reaction will be without regard to what makes good tactical sense by the character, and in that sense it can reward the players who chose to use covering fire in combat.
Simplified Replicant Table:
1: Anger/Attack
2: Deep Despair
3: Despair
4: Self Destructive Reaction
5: Emotional Reach out
6: Massive effort followed by Deep Despair
The downside of this improvisational method of interpreting stress failures and making them based on the situation and the makeup of the character that is broken by stress is that the players are not guarantied consistent combat results in the success of causing opponents stress.... I guess taking out Health points is more reliable. As it should be!