But if you only use one unit type then spie attacks will mess your units up even more. if you lets say have infantry and trucks then one of them would not get spie attacked so you would still have some healthy units at least. And its also harder for a player to kill more then 1 unit type attacking them. If some one attacks me with all trucks then im just going to build a lot of emp units. To me its easier to do that then it is to build emp for the trucks and then build anti infantry units. I would have less to kill what they send at me. That's how I look at that but you guys might see it in another way.

he means one type per squad most vets recommend having two unit types in your army

Using infantry as an example.

Damage totals from 1 armour, 1 damage and 1 ranged infantry per round:

Round 1:
Total damage inflicted by armour: 0 (cannot fire yet)
Total damage inflicted by damage: 0 (cannot fire yet)
Total damage inflicted by range: 4

Round 2:
Total damage inflicted by armour: 0 (cannot fire yet)
Total damage inflicted by damage: 6
Total damage inflicted by range: 8 (4+4)

Round 3:
Total damage inflicted by armour: 2
Total damage inflicted by damage: 12 (6+6)
Total damage inflicted by range: 12 (4+4+4)

Round 4:
Total damage inflicted by armour: 4 (2+2)
Total damage inflicted by damage: 18 (6+6+6)
Total damage inflicted by range: 16 (4+4+4+4)

Round 5:
Total damage inflicted by armour: 6 (2+2+2)
Total damage inflicted by damage: 24 (6+6+6+6)
Total damage inflicted by range: 20 (4+4+4+4+4)

As you can see damage hasn't actually done more damage until round 4, while most battles last 1-2 rounds, with a particularly bad battle possibly lasting 3.

As you can see, that +1 range that Range has over Damage really does make a lot fo difference.

and to answer the question about wikis:
http://wiki.battledawn.com

You have a good point but most good players don't get into situations when their squads can be hit by spy attacks.

I always have SP on OP's if my entire army is on them. So even though my units are only 1 chasis, they can't be hit by a spy.

One of the best things that i've found to use, especially in the start of the round, is a vehicles range/armor combo with either 10/11 range and 5/4 armor to a squad, and always use concussive armor, due to the fact that it is hit first in battles, thus taking the blows for your range.
Having all vehicles is good, especially a the start, when noobs are building inf armies... now i know that doesn't make sense, but look at it logically... The only time, in my experience, that a full inf squad will take down a full anti-inf vehicle squad (of my combo), is when the inf are anti veh, and are packing at least 13 range/17 armor (all beam).... no damage.That battle will result in both sides dieing. If you increase that to 14 range/16 armor, the inf will keep 2 range from the battle. If you change out the 16 armor for 16 damage, both sides will die... just showing that armor is best espeically when defending its range counterparts
however, if you look at a battle with strait up 30 damage inf, they lose... but if you change that to 12 damage/18 armor, they win with both sides dieing...however, you must increase your damage to 15/ 15 arm to ensure that you have some surviving troops, and even then, its only 1 damage.
If you expand that to 15 squads of each combo, taking 13/17 range squads, the range will win, and have 15 range left over. However, if you take 15 of the 12/18 damage squads, they will actually LOSE the battle...
So on the large scale, if you are playing even matching squads, damage will lose

So if you look at it as inf facing veh, if you were to build damage and armor together, it IS doable, but you should only do it if you are facing your advantage chasis...
If you are experienced at all, and you, like most of us, dont like losses of your 'muscle units', then you would build a good range/armor combo, and just leave the damage out of everything.

If you are worried about spy attacks killing all the vehivles, then do 1 of 2 things...
1) just leave your spy on your colony and get good protection
2) be active and dont just leave your troops at one spot.
-If you are leaving them at home, and get spied, its not too terrible unless you are under attack... your troops can regenerate the HP over time... so just let them rest for a day or two

side note: Building only veh is pretty good until the world wakes up and starts buildin other stuff, then its your choice as to whether to build tanks or inf... my preference is to build inf squads after a while, firstly because they are cheaper after the overhead kicks in XD, and secondly, because they can destroy any other vehicle combo stuff that i may have to face

This strategy apparently works, because its how i got up to #1 in F1 :S