Recommended mods: either Sharp Blades - Spectral Shield - Elite Equipment or Accomplice - Spectral Shield - Elite Equipment.
If the player uses this buff, it is recommended to keep the level fairly high (without going over CA level without penalty) to ensure the skeletons can kill at a decent speed.
Another way to use the skeletons (if you are not concerned with their killing ability) is to draw aggro. Keep the CA level low and allow the skeletons to enter the fray first. The skeletons will draw the aggro (even while 'dead') and will allow you to slay enemies without drawing too much attention to your character. Just make sure the enemy sees the skeletons before they see you. This will also work on bosses.
Mod with Accomplice and Commander and use with Rallied Souls to command a massive undead army.
Pros and Cons
Skeleton units will do damage instead of the player which provides strategic opportunities.
If a skeleton is killed, it will return to life, but it will take time for them to resurrect.
If a player moves too far ahead of the skeletons, the skeletons will then teleport to the player.
The summoned skeleton units will roam around freely, usually not attacking the same enemy unit a player does. (No longer true in Ice & Blood.)
Too many skeletons can get in each other's way, especially if a player is using Rallied Souls at the same time.
Requires a high combat art level for good kill speed from skeletons, as this increases their damage.
Can attract extra attention from other enemy units
Any enemy Area of Effect or Reflect spell that causes damage to skeletons will also damage a player even if while invisible (using Shadow Veil)
Skeletons do not run very fast and it can take a few seconds for them to teleport to a player and then find the enemy.
The Sharp Blades mod on Neither Allegiance has a fixed 43-44% Increase to damage. this mod is not affected by Astral Lore or Combat Art level.
As of Ice and Blood, the skeletons can be told to stay close to the SW or to a certain range. They also can be told to seek out individual targets or gang up on a single target opponent. Splash screen tooltip follows:
"You can give orders to your familiars and companions with SHIFT + mouse button, they will attack. With # (default) you can specify the radius in which they will attack on their own. With - you can specify if they attack as a group or individually."
So: pressing # will change the radius from near, medium to far, back to near, then to medium...
Pressing - will toggle between the skeletons attacking the same target or each taking their own targets.
And.. SHIFT + mouse button will direct the group's attacks.
No modifications, no skills, naked, all stats between 25 and 35 (i.e. a nearly-new character).