Many thanks for your answers.
the actual system (12 or 6 dice) is based on the Armour class system.
So if someone want to use the "1 die per figurine solution" (still in the unit) there is the need to change the original LR armour system, which won't work went the unit will lose too many troopers.
A 8 men unit, can't kill 3 knights of armour 4 class, (but only 2) even if all the members make a hit.
So why not change this into a save throw for armour class instead ?
Like WH games, if i remember well.
Throw 1 die for each hit, received by the unit, on the Armour class.
For a MMA with Armour 4, that give us :
From 1 to 4, no hit confirmed.
to 5 - 6, the hit is a true kill.
and so on
Does it's could work ?
Does anyone try this kind of changes ?