Troop Vs. Troop
Almost everytime you attack and player or cpu base you will find that most of them employ a fair amount of troopers. These may range from Riflemen to Hercules. One basic rule to keep in mind that when dealing with these with normal troops you should keep with you a bigger group of troops. Strength in numbers you know. Riflemen and Heavy Gunners are typical infantry and are great in numbers. Flamethrowers are best taken out quickly as they can take out entire groups of soldiers in a matter of seconds. Sniper are great for takeing out infantry from long range where they can pick infantry of one by one. Hercules are the juggernauts and should be dealt with carefully as these are difficult to take out with vehicles also. RPG troops are not advised in any infantry on infantry scenario as they are weak in giveing infantry damage and are usually used for vehicle combat and base destruction.
Vehicle vs Troops
When using vehicles to fight troops it is advised to use vehicles with guns on them as explosive weapons do minimum damage. Beware of Mortar Troopers as they can kill vehicles in numbers. Target them first if needed.
Vehicle vs Vehicle
Its generally the one with the most tanks wins. Use honey badgers to spins circles around larger (and usually slower) tanks.
Aircraft vs Vehicles
Aircraft rule all land vehicles except Gatling Trucks, Flak Tanks, Challengers and Hover Tanks. Use them to destroy pesty damage dealing tanks. Beware the Behemoth that, when destroyed, will spawn 2 Reaper Drones that will attack nearby aircraft.
*DOES NOT WORK ON STAND GROUND TROOPS*
Baiting is the most important trick to learn in the game because when successful you should not lose a single unit from other units, but you must be skilled and quick. When troops like Flak Tanks are entrenched in the defenses it makes attacking with air a living hell, or when Stingers and Gatling Trucks are lined up so you can't get a single Hellfire Missile through, so how do you get them out? You bait. Most of the time with tanks a player will put it's stance on normal, and when you want to get rid of that tank you send in a ground unit of your choice. The tank will follow the troops send the tank on a wild goose chase straight into a air unit you have waiting to destroy them. As for Flaks if the player is stupid enough to not put them on stand ground, then the Flaks will follow the air unit so send that on a wild goose chase into a ground unit you have waiting to destroy them. Baiting is usually the only way to take out an entrenched unit in defenses, so learn how to use it.