Pricipr I-go You-go (as in chess game). Not modern game design, but understeandable by everyone. Battle divided to turns, turn to phases (preparation, movement, shooting, assaulting) probably you know that.
For resolutions - compare 6-sided dice and difficulty of action (or miniature skill).
For example, 50% chance is 4+ skill (result of 4 to 6)
With one D6 dice we can make 6 levels of skills (4 of them can be actually used in game)
- 6+ critter
- 5+ weaky
- 4+ warrior
- 3+ veteran
- 2+ elite
- 1+ god
Having that, we can represent this:
- 1) Ability to hit target (shooting skill)
- 2) Evading of fatal damage by target (defence skill)
- 3) Visability modifications (+ - to hit)
- 4) Survivability of target modifications (+ - to wound)
Generic warrior have all skills 4+ shoot, defence, throw greanade, hand-to-hand and other available actions.
What weapon warriors have - will be dscribed later.
Why so primitive? Because now it's enough. If it will not enough it can be easily expanded.
With this system, we can represent units from Warhammer 40000 game (and not bothering will thir many stats):
greenskin grot = weaky
IG guardsman = warrior
space marine = veteran
Nurgle terminator = elite
There is no "wounds". Model can continue to fight or it wounded once and out of action.
For shooting this secuence:
1) Choose target, check range and line of sight, if ok then shoot at it
2) d6 to hit + sight and range modificators
3) d6 to wound (rolled by target controlling player, to not became bored) + defence modificators
Total 2 rolls per shot.
What it bring to us? Compared to Warhammer, armour and cover can work together. It's little more realistic.
What You See is What You Get -
Your miniature should clearly represent what it representing
Veteran squads should be different from recruits (badass, weathered, additional equipment, more muscular for example)
Rifle is rifle, machine gun is machine gun, pistol is pistol etc.
Commanders should be recognisable from other soldiers. IRL, that will cause sniper kills, but we need to quickly find our commander amongst the squad. So, it;s not bad to make commanders more fansy and stand in some heroical pose.
Sometimes it's impossible to make all war gear on miniature. For example, your list includes one flamer, but you don't have any flamer miniature. In that case, write "FLAMER" on small paper and put it on generic rifleman. It's not cool, but at least you and your opponent will sure what it is.