I know that when making a squad you set it up: Arm/Dmg/Rng
9 / 0 / 21

But should I mix weapon type in the same squad? Should I have a squad mixed with beam and explosive or have an AV squad and an AT squad?

when making your squads, have all your range be one thing. and your armor be all concussive, for example:

21 beam range inf
9 concussive armor inf

11 exp. range veh
4 armor concussive veh, follow that order

Its easier if you don't mix. So if you scan for example tanks in your target, you can send anti tanks.

Mixing only hurts your squads. MAke all the armor concussive, as concussive gets hit last in the battle reports

There are some argueing about the squad setup, but here are some of the most used squad setups that I've seen.

- all armor: this is for the beginning of the era (less than 100 ticks) and for score boosting. I used this in the last era on M1 and my score got from 500 to 1130 in 200 ticks.

- 3 range : 2 armor: this is the most used one (or 2 range : 1 armor, it's not different much), the basic of this is let the armor die and the range kill. Then u can reinforce ur squad with the armor units, which is the cheapest one.

- 3 range : 1 damage : 1 armor: some ppl believe this is better than the 3:0:2 setup. Battle simulations prove that this setup does defeat the 3:0:2 in some occasions.

And for the armor unit's weapon. I think anything will do, since they will die before they inflict any severe damage. Just don't use different chassis (eg. armor tank with range infantry).

Hope this will help ^^