Hello, I am interested in helping you create rules for such a scenario. To begin, I have some suggestions for unit and weapon rules.
D6 system
Land Units:
Infantry
cost-3 ipc A1/D2/M1 (A2 when supported 1 to 1 by artillery)
Mech Infantry
cost-4 ipc A/1/D2/M2 (A2 when supported 1 to 1 by artillery)
Artillery
cost-4 ipc A2/D2/M1 (first strike)
Self-propelled artillery
cost-5 ipc A2/D2/M2 (first strike)
Tank
cost-6 ipc A3/D3/M2 (can blitz)
Commando
cost-5 ipc A2/D2/M1 (target selection on a roll of 1)
Air Assault Infantry
cost-4 ipc A1/D2/M1 (M3 from airbase)
Surface to air missile
cost-6 ipc A2X3/D2X3/M1
Weapons:
Rockets
Cruise missile
cost-8 ipc M2 (launched from cruisers, destroyers, airbases and naval bases. Role 1 D6 for damage inflicted, 1-2= 1 hit, 3-4= 2 hits, 5-6= 3 hits.)
Anti-ship missile
cost-8 ipc M2 (launched from cruisers, destroyers and naval bases. Role 1 D6 for damage inflicted, 1-2= 1 hit, 3-4= 2 hits, 5-6= 3 hits.)
Sub launched ballistic missile
cost-12 ipc M2 (launched from subs. Role 1 D6 for damage inflicted.)
Intercontinental ballistic missile
cost-20 ipc M10 (launched from missile silos. Role 2 D6 for damage inflicted.)