As I see many people say that using Amour:Range= 3:7 is the best, but I find that if we use same resources to produce army, using only damage army is ever better than the 3-7 mix of amour and range.

Can anyone tell me why damage units are not preferred to be used?

Damage units are best when you have an equal battle at hand but are not that useful in mass battles
Say I have 90 range tanks and 10 armor and you have 90 damage tanks and 10 armor, what happens is my range gets the first attack so your armor and some damage units are already destroyed before they finally attack since damage attack second in a battle

Although this is a highly debatable topic, range is still prefered to damage though I think its due to individual preferance
What I do is I create maximum range, as much as I can with few supporting armor and when the overheads get too high and range become too expensive for me I then shift over to damage. To me this has been pretty deadly so far
Or you can limit as well, I sometimes say for every 3 pure squads of range I have, I create 1 squad of damage so if I have 90 range infantry, I create 30 damage infantry, etc...

Many players use damage in their squads. While damage might be useful when you face people that have only armor, you’ll have a hard time fighting someone with range. If someone sends enough range, they can take out your damage without you doing ANY damage to them. Most people will always try to have rounds that last only 1 round, so that they take minimum losses. In battles like these, your damage will be just useless. Therefore, I think people shouldn’t make damage, but should go for a mix of range and armor. Damage might work initially when many people don’t have range yet, but in the long run and in the big battles it just fails.
Damage should only be used for spams, it can be effective in equal battles lasting 3 rounds or more but those are not the kinds of battles you should be fighting.

You can always come up with your own ratios, but most people tend to go for 21-9 for inf, 11-4 for vehicles and 7-3 for heavies. 21/11/7 being range, 9/4/3 being armor. It’s been tested over and over again, these are the best ratios. Of course a small change won’t make that much of a difference, for example going 22/8 or 20/10 for inf or 10/5 for vehicles.
There is no "best chassis" only the chassis that best suits your style of playing.

I think this topic should be moved to the "Players Helping Players" thread

while it maybe true that it can defeat the normal 3:7 build, in normal circumstances it will have a lot of loss and thus is not preferred.

the reason why 3:7 is chosen as the best build in general, is that it can maximize the damage while minimize the loss when outnumbering the enemy (which is wat everyone should aim at).

Comparing 7:3 (r:a) squads to damage builds on a 1 squad vs 1 squad ratio fails to grasp why 7:3 is used.

In the long term, any player should aim for maximum battle efficiency. The best way to achieve this, is to make sure all of your battles end in 1-2 rounds (preferably 1). Only in extreme situations (such as a rare opportunity to kill a large hostile force) should a player deliberately enter a 3+ round battle.

Let's use tanks as an example: Range units deal 12 damage per round, damage units deal 18 damage per round.

Round one:
Range unit fires and deals 12 damage (total of 12 damage)
Damage unit cannot fire yet

Round two:
Range unit fires and deals 12 damage (total of 24 damage)
Damage unit fires and deals 18 damage (total of 18 damage)

Round three:
Range unit fires and deals 12 damage (total of 36 damage)
Damage unit fires and deals 18 damage (total of 36 damage)

Round four:
Range unit fires and deals 12 damage (total of 48 damage)
Damage unit fires and deals 18 damage (total of 54 damage)

My point? A battle has to last for four rounds for a damage unit to actually outperform range. If your battles are lasting for that many rounds, then your battle efficiency is terrible. Four round battles are the sort of battles in which all of your armour and a serious chunk of your 'damage dealing' (be they range or damage) units are killed.

So, in conclusion, that damage based squad might be cheaper and even stronger in a 1 squad vs 1 squad scenario, but if you always aim for 4+ round battles (the only battles in which damage is better) then the cheapness of your squads will do little to offset the cost of almost completely rebuilding every squad you send into a battle.

George can u plz explain ur 2nd paragraph with an example ?
Tom can u explain in more detail?
Kish8 can u explain with another type of chassis?

What are you unclear on? I may be able too explain for you.

The simplified version is this -
Damage units only do more damage than Range units in battles that last for at least 4 rounds.
Look at your recent battle reports, and see how many last 4 rounds or more. It's probably not many. Also, your losses in those battles are probably massive. That is why damage based squads aren't great.

I just went to battle simulator
I took 50 armor 50 damage & 50 range to attackers
then i took 75 armor & 75 range to defenders
result was attackers won the battle

Then i took 50 armor 50 damage & 50 range to defenders
then took 75 armor & 75 range to attackers
in this case too attackers won.
In both cases attackers & defenders had infantary
How's this possible?