So, for those of you who remember my go at the Squadlin as a mob unit, here's an attempt at a more difficulty-accurate, arguably less complex go at the same subject. As an additional bonus, this gives XP more accurate to the difficulty of fighting the Mob.
This method is what I'm gonna call the
Aggregate method of creating a Mob.
Step 1: Figure out your base creature and approximate unit size. For this example we are going to be doing two groups, a unit of 20 Guards (A Guard Detachment) and a unit of 5 Veterans (A Veteran Squad).
Step 2: Multiply the XP per creature by the number of creatures in the Mob, and then figure out the Adjusted XP for the encounter. This gives us 2000 XP for 20 Guards and 7000 for 5 Veterans.
Step 3: Round to next CR. This gives us Challenge 6 (2300 XP) for a Guard Detachment (We can assume there's an officer or sommat in there) and Challenge 11 (7200 XP) for a Veteran Squad.
Step 4: Use the DM's Guide to figure out appropriate stats. Keep the following in mind: AC should remain the same as the base creature, adjust it minutely if you
have to. Give it a large number of attacks instead of a few bigger attacks, and note that it can split between ranged and melee options. For exceptionally large mobs, limit the number of attacks that can be made against a single opponent and give it two turns per round (Remember to factor this in when checking Damage Per Round. Give it the Mob trait. (Mob (X): Immune to status conditions (Except for Frightened) if they would affect less than (X) number of creatures. Takes double damage from Area of Effect attacks.). Figure out an appropriate size. In general, Mobs with X of 5 or less are Large, Mobs with X of about 20 or less are Huge, and larger mobs are Gargantuan.
Examples