MOP
Every NPC needs a mop.
Motivation: Why is the character here in the story? What motivates them to act?
Objective: What does the character want to accomplish as a goal in the story? What is the character's overriding goal they must achieve?
Personality: How the character acts as well as their personal appearance.
These three traits help define an NPC. Savage Worlds helps a lot simply due to the Hindrance system which tells you a lot about the character's personality. Edges can also help. A Rich edge having character is going to dress better than one with the Poverty Hindrance.
A Personality Shorthand: Representative Animals
An idea from the Happy Jacks RPG podcast about specifically personality is to steal the mannerisms of a representative animal. So a snake character might talk with a lisp, pretend to be an ally, then betray the characters at a key moment in some way to accomplish their goal. At first they save a key party member and work to get inside the heads of the PCs that they can be trusted. The NPC works with the group for a while until their goal is within reach, then comes the backstab.
A lion might be a loud mouthed but completely heroic and loyal character who fiercely defends the group. An accent like the cowardly lion from Wizards of Oz might make the character stand out, except that they are Brave, sort of post transformation.
A weasel might be a true coward with the yellow hindrance who can be bullied by the group into getting what they want from him. He might also be vengeful (minor) and use his bureaucratic or political power to block the characters later on in the story, making for a plot obstacle. He might stutter or wheeze in some way like a weasel as a mannerisms.
Once you visualize the animal in your mind, jot it down in the character's notations so you don't forget the animal totem personality.
The most likely reason to need the PCs to go on these missions in the first place is that either the soldiers are too busy with other tasks, or aren't up to handling the missions the PCs are being given. If the former, it's easy for your general to say something like "I'm very sorry, but because of the raids on the outlying farms and the bandit threat on the main road, I can't spare any soldiers for your mission at this time."
If the latter, the PCs should be able to tell the soldiers aren't powerful enough from other information -- perhaps they come back with significant injuries from fighting those road bandits, and the expected enemy for the upcoming PC mission is a creature or group that could eat the bandit band for breakfast.
Either way, the way to do this is to make the soldiers unavailable as backup for the PCs -- and certainly the general won't take time or (very slight) risk to himself for things other than his main mission, which is most likely what military organizations usually do: protecting the citizens.
Best Answer
Beating an encounter can include the enemies fleeing or surrendering.
Role playing NPCs or enemies where murder or death are not the only options is an effective way to mitigate the tendency toward murder-hobo player parties.
An enemy that surrenders and/or flees counts as defeated. Make that clear from the outset session 0. They party gets the same credit as if they had killed the creature. Additionally, it offers up the opportunity for more loot and role play.
Additional Benefit
Demanding the opponents doff their armor or give up their weapons in their still serviceable form as terms of surrender.
Persuading or intimidating the opponents to reveal information before turning them loose. Such as the location of a horde or a clue in a side quest that would have otherwise been harder to obtain.
Additional Role Play
Make note of opponents that were defeated and allowed to live or escape. Make the circumstances of that come back around. If the player characters were benevolent or malicious, that information will spread. Perhaps they encounter the relatives, friends, or allies of an enemy they allowed to surrender. The treatment of the previous encounter should affect the subsequent interactions.
Run Away! using the optional chase rules
Determine the conditions that a group of enemies or NPCs would disengage or flee prior to the encounter. Figuring out what a show of significant force would be to the NPCs is a reasonable staring point. E.g. "If their best fighter goes down, they run away." or "Demonstrating a command of the elements inspires awe in the creatures and they lower their weapons."
It is particularly impactful if the characters have discovered the conditions that can manipulate the situation previously in the story, and can then apply their knowledge to great effect. E.g. "They might have discovered that Krog the Krogdarian is immune to fire, but fears lightning." or that "Meghanna, ironically titled the 'merciful', is particularly keen on avoiding a fight if not confronted in public."
When running away, it is a different mechanic than a fighting withdrawal. The Dungeon Master's Guide includes an optional rule for chases that makes for a different flavor should the characters find the need to give chase: