I am pondering over how to introduce a couple of new unit types into the game and I think they might have some wider appeal. Anyways, I figured some input would benefit me and others who may want to use the same ideas.
Swarms are represented by a larger base with many models. The exact number of models is not relevant as the swarm is abstract.
Each swarm base has a suppression value. Unlike normal infantry, when a swarm fails an armour save it gains a suppression marker (even from melee attacks). Once the swarm has a number of suppression markers equal to its suppression value it is considered destroyed. Like all suppression markers, a swarm removes all suppression markers after an activation roll (successful or not).
If a swarm has a shooting value it represents the total shooting value of the swarm base, not the shooting value of each model.
A swarm has a melee value, the number of models a swarm may engage in melee. A swarm only needs to be in physical contact with one model of a unit to engage a number of opponents equal to it's melee value.
If a swarm unit is within unit coherence of other swarms when activated, it may absorb those models/units to form a larger swarm unit. The 50% mark to be considered broken is based on the new unit size.
Behemoths are large living creatures tougher and more resilient than most. A behemoth can suffer damage and suppression from the same shooting attack to represent the large size. Like a vehicle, a behemoth is immune to small arms if it has a save of 5+ or greater. When a behemoth would be considered a casualty (fails an armour save when the unit suppression value has been reached) it is instead injured and suffers a -1 to all rolls. An injured behemoth is removed as a casualty if it suffers a second injured result.
A bit wordy right now, but just the initial ideas to get pared down.
Any input would be appreciated.