New way to BI?

Hmmm…

Done

Legends of Arcanis Mass Battle Rules

Battlemap conventions
When using a hex grid or square grid, each unit takes up one space. Every 20’ (or part thereof) of Pace equals one square/hex.

Without a grid, each 10 creature (or stamina for 1 stamina creatures) receives a 1×1” square base. Every 10’ of Pace equals 1 inch on the table top.
Clock
The clock is still used, but some things are slowed down due to coordination requirements. See each section for adjustments. This can make heroes feel like heroes, as they can continue to fight as individuals (but will still be overwhelmed if they pick the wrong fight to join).
Unit size modifier
To model the advantages of mass numbers or staying power of a few more powerful creatures working together, apply the following table to all die rolls (Action roll, Damage rolls etc) that include an Attribute die and all Defences. The formula is SQRT(x)-1.
This modifier is also applied many other components to reflect the difficulties of getting large units to act coherently.

#Creatures Modifier
1 +0
4 +1
9 +2
16 +3
25 +4
36 +5
49 +6
64 +7
81 +8
100 +9
121 +10
Movement
Movement in mass battles works the same as tabletop. Apply the Unit Size Modifier to all movement action speed costs. IE. A 100-man unit of legionnaires moving their Pace would cost (4+9) = 13 ticks.
Combat
The same as Movement. Apply the Unit Size Modifier to the speed cost of the combat action chosen.
Stamina is applied against whole creatures and overflows into the next creature. If a Wound is caused, it kills enough creatures to reduce the unit size to the next modifier down before any Stamina damage is applied (ie: a unit of 100 creatures is reduced to 81 creatures before Stamina damage). This does make larger units more vulnerable to Wounds but also reflects that sometimes Fate plays her own game.
Example Combat:
A 100-man unit of legionnaires perform a basic attack with a Gladius at (5+9) = 14 ticks.
The unit (being experienced of 1d8e quality and +3 skill) would then attack with 2d10 1d8e+3+9 against their foes Avoidance Defence (which has also been modified by the Unit Size Modifier).
Damage would then be 1d8 1d8e+9 vs the foes AR.
(e = exploding die)
Detachments
A commander can break off portions of a larger unit (usually to deal with heroes or other small targets) but they still move at the slower Tick cost of the parent or detachments actions (like a group of Minions).

Using the Battle skill
The unit commander on successful use of a Battle skill roll may choose to change the Unit Size Modifier by +/- 2 (their choice) to a minimum USM of +1.
The target number is equal to 15+USM.

Final words
As you will notice, larger units will easily grind up smaller units unless Larissa is smiling. Individual heroes can make a big contribution due to the faster speed of their actions, but will also struggle to make a dent in a large unit.