Tried it once. My ancient egyptians/archeologist's hybrids against a martian mech army. Assigned seemingly sensible values for guns/magic staves etc.
My army:
"Halftrack" truck with reinforced plating, hero mummy with lazer scepter, battering ram, 2x co-axial rifles, 8 skeleton gunners in the back each with their own rifle and a shield crystal. My main points sink.
Winged crocodile steed with another mummy on it. Bites and the rider has another lazer.
Archaeologist truck with frontal rifle mount, bulletproof windshield and rear mounted twin linked rifles.
Biplane with 2 forward facing rifles and a tail gunner with dual pistols.
All from the ancient egypt set and fully scratchbuilt.
Enemy army:
One of each mech in the life on mars set(5 in total), no further modifications.
Battlefield was a rocky desert. Objectives was to kill the enemy.
I start with both my ground vehicles in cover and my airborne ones flying between the cliffs to prevent a smaller target for the enemy mechs. My mate moves in to bomb me with both his flier and the convertible shutte, confident in his air superiority. Turn two saw me attempting to navigate through the rocks while preventing him from getting a clear shot at me(all his mech guns were up to ~36'' range while my gunpowder didn't reach beyond 18'' at best. His turn he managed to get his flier over my ltv, wrecking the enngine and kiling the driver. My turn, the gunner on the now crippled vehicle shoots the flier but fails to take out more then one engine. My halftrack makes it's first hit and run on one of his bigger mechs and takes out it's claw. The winged crocodile swipes at his smallest mech and eats the pliot. The biplane ineffectively tries to strafe his other mech. In retaliation it's blown out of the sky next turn. The crippled flier makes another pass at the immobilized ltv, failing to destroy it but blowing off some turret shielding. The larger mechs start hunting for my hiding halftrack. The hybrid ambushes it by flying over a cliff and pounding it from directly above, exhausting most of the shielding crystals. My turn the ltv turned bunker shreds the open cockpit-ed flier's pilot causing it to crash into a cliff with a sizeable explosion. Thankfully, nobody else was hurt but nothing can be salvaged. The halftrack legs it from out under the airborne mech, plinking at it with all of the skeleton's guns. This destroys a wing, which forced it to land or fly in circles. The croc swoops in for the kill and rips another head off, sending the mauled machine plummeting, causing severe damage to it's leg and remaining wing, immobilizing it. Not that it matters, i have nothing to capture it with. The mechs destroy the croc with concentrated fire and one gets in range of the ltv and fires, blowing up another useless tire. In my turn the halftrack flanks a mech and unloads it's entire arsenal into it's back. This blows up it's engine, destroying it. The ltv gunner bails and makes a dash for the little mech that had it's pilot eaten by the croc in turn 2. He didn't make it far before being shot to pieces my opponent's very next turn. The last turn of the game saw my halftrack coming up to the side of the mech and blowing out the pilot by means of a mostly open cockpit.
3000BC prevails over 3000AD! Not really, the system is quite clunky and very unbalanced for flat vehicles with large plates and many tiny guns.