Despite the Confederation being the main enemy, same faction battles are still very possible and they happen quite often. Being equally matched in terms of advantages and disadvantages causes the battle to rely much more on skill. Many advantages are negated such as:
Resource collection speed
Long range
Stealth
Speed and maneuverability
Mining
There are some tactics that are more effective than against confederation (such as coyote rushes for example) and some that are less effective (such as using helicopters at sea). Resistance units that excel in same faction battles are:
Dragonflies
Barracudas
Albatrosses
Dragonflies take advantage of the fact that jaguars lack anti-air. Barracuda is strong because only other barracudas can effectively kill it. Albatrosses make accurate hits on stationary jaguars. Several gameplay styles and tactics will be listed below
Attacking with coyotes, or with coyotes and grenadiers prove effective because of the speed and quick preparation time. When attacking an unprepared enemy, it is much easier for a successful attack due to the lack of bunkers. Normally against the Confederation, bunkers can be quickly constructed and once they are complete, prove far too difficult to break through under early rush conditions. However, sniper towers are much easier to destroy due to less HP, armor, and overall efficiency against units in general. Guntowers also do not have as large damage output, rate of fire and explosion radius as rocket towers. Guntowers kill fewer units per unit time, hence it is easier to break through the defenses of a resistance player.
Given that the main unit composition of a resistance player will have plenty of jaguars, this leaves vulnerability against helicopter raids. Against the Confederation, dragonflies suffer from Zeus' anti-air and typhoons, which deal much greater damage to aviation than porcupines at a longer range. Jaguars are also an easier target than Zeus due to less HP and armor. Porcupines have a CP of 3, the same as a dragonfly, unlike typhoons which have CP of 2, and can be massed in larger quantities. Also at the base, sniper towers are much easier to destroy than bunkers, and the buildings of resistance have less life and armor overall. Dragonflies are effective on land against resistance, but are not good at sea due to alligators having anti-air.
Against the Confederation, they have much more powerful anti-air in all respects, and the large HP and armor of the albatross against resistance which have weaker air defense proves a large advantage. Against the resistance, albatrosses die much slower due to the weaker anti-air. Albatrosses can more easily pierce the base of a resistance player. They also perform much better against JCP as compared to their performance vs Zeus shield, which takes much less damage.
Submarines of resistance can usually only be killed by submarines of an enemy. This is unlike the case where Vikings, which are much cheaper, have lower CP and production time, easily kill submarines in mass or 1v1. This means that, basically whoever has more submarines in a confrontation wins. Also, if an enemy has unupgraded submarines, this basically guarantees victory if an enemy is unable to pierce the base very quickly with alligators.
Now stands the main combat scenario, fog vs fog, JCP vs JCP. This indeed depends on who has better skill. The ability to maneuver units and force fire accurately can be the difference between victory and defeat. In same faction battles as resistance, battle outcome is usually decided by rapid and vicious combat of fog vs fog, fog wars. The better player normally wins, and sometimes luck can help,
In general, 2 level 3 assault factories and 1 level 3 special factory is the main build. This can be done with 3 level 3 assault vehicle factories as well for a full scale war. It is possible to go toe to toe, head to head to decide who wins, pure jaguar and chameleon against jaguar chameleon. However, there are a few units that can be used to shift the balance of the battle in your favor:
Riflemen
Dragonflies
Porcupines
Albatrosses
In a fog vs fog scenario, riflemen can be used to pierce enemy fog clouds and reveal enemy tanks, which negates the need to force fire. The enemy tanks also have to take damage from their own splash when trying to kill the riflemen. An army with fewer jaguars but with a ton of riflemen, can often succeed against a larger quantity of jaguars because of this
In a fog vs fog scenario, using a large number of dragonflies unexpectedly can turn the tide of battle due to the low porcupine count in fog wars. Most people opt for masses of jaguars without porcupines for a full scale land war. This leaves vulnerability to fast and unexpected dragonflies, which on large maps can chase and effectively annihilate armies with ease due to shortages of anti-air.
Porcupines protect against enemy dragonflies and enemy riflemen that pierce your fog cloud. Since porcupines can't force fire, any rifleman that comes into view is instantly targeted by the porcupine's machine gun. Even if there are some dragonfly in the area, they can also be shot at due to the porcupine having two weapons. In emergency scenarios, porcupines can be used to pierce enemy fog clouds as well
The albatross, having a large amount of life and armor, dies slower against resistance. It also has chances to deal massive damage to enemy units under fog. This isn't the case against the confederation, because bombing an army of Zeus under the shield, even twice, does not cause significant damage. Jaguars in siege mode are an easy target for bombing runs, hence it is also easy to erase a large number of units with bombers.
Overall, red vs red is generally more action packed and has much more battle confrontations during a match. It is necessary to adapt and adjust to the type of gameplay and fight accordingly. However, someone with less upgrades and lower commander skill level becomes extremely disadvantaged, and a higher quality of gameplay would be required.