Jeffy and Weasel

Use: The best way to use these little scouts is to build about 3-5 of them the first thing you do when you get your vehicle plant up. Then send them out to look for your enemies. Dont micromanage them until you see your opponents dots on the radar. Else you will lose more in construction than you gain in destruction with them. These guys are really fast but they dont have an impressing acceleration so keep them going around as much as you can. Dont try to take out solars with them. Settle with his metal extractors. One of these little things can win the war for you if you have luck in destroying his metal extractors.
Important stats: Jeffy vs Weasel: Jeffy is a bit faster and cheaper and have less build time. Weasel has some more armor.
Preferred side: ARM
Flash and Instigator

Use: These little tanks are useful throughout the whole game if it is a landmap. In the early game you crank out a shitload of these to try to wreak as much havoc as you can and hopefully kill his commander too. Their strength is that they can go past his defenses in the early game where there are no dragonteeths and hit his valuable resources. In the midgame and late game these units are still useful for defense. With the same amount of metal an army of assault tank will beat most land units on open ground. So meet his attack about half your plasma-battery range and use your tanks as cheap and fast dragonteeth. Goliaths or other heavy stuff will have a hard time moving around and you dont really care if your plasmabatteries kills your little tanks. But avoid using berthas/intimidators when using this defense since all the debris will blow up and the way for his heavy stuff will be cleaned. In the late game assault tanks are also useful as cannon fodder since they can take a lot of punches so your heavy stuff can roll in and fire at long range without having to deal with enemy fire.
Important stats: Flash vs Instigator: If you see to the statistics you would think instigator is better than flash. Flash is cheaper and have less build time but doesnt do nearly as much damage as instigator. But when you play you will experience that flash targets a lot smarter and get their shots away before they die when instigator is trying to find where he has his turret while getting a bunch of shots at him.
Preferred side: ARM
Stumpy and Raider

Use: Medium tanks are not useful for very much. They can replace assault tanks when your opponent builds too much dragon teeth or solars since they can shoot over it or even destroy the dragon teeth. Usually i build a few of these to make a hole in his wall of dragon teeth so my assault tanks can enter his base. They have one more use and that is to blow up stationary targets while your assault tanks distracts his defenses. I have heard rumours that medium tanks do more damage if they get closer to the enemy and they already do a lot more damage than assault tanks so they might be effective to kill of those immortal solars.
Important stats: Stumpy vs Raider: Stumpy as usual with arm troops cheaper and faster but the Raider has less build time. If you want to use medium tanks as skirmish troops i would say Stumpy is the better one but since I only use them as DT cleaner the Raider would be a better deal beacause it can take one more shot from a LLT than Stumpy can.
Preferred side: CORE
Samson and Slasher

Use: The obvious use of these vehicles if of course air defense. But their superior range can be used in offense too. Combined with medium tanks they can make a good job against a well defended base in the early game. Their missile can blow up debris quite fast and make more way for your assault tanks. You need to crank out at least two of these very early in the game to defend against commander-snatchers unless you are very good with the D-gun. Missile units can also be very useful defending islands since your opponent gets frighten when he sees about twenty missiles hit his ships repeatedly.
Important stats: Samson vs Slasher: Samson is a bit faster than Slasher but who needs speed when you got range? Slasher is cheaper, has less build time and do a little more damage with their missiles.
Preferred side: CORE
Triton and Crock

Use: The use of these tanks are VERY few. If theres a lot of water on the map it can replace heavy tanks since they have almost equal weapons, a bit slower though. Where they are good are when its a small map, since they move to slow under water to be effective, when they can hit your opponent when he only got a bunch of defenders and samsons. If you have TACC the ambiphibious tank is almost totally useless unless your opponent has a lot of on-sea defenses and no underwater defenses(fat chance!). The hovertank will do the job a lot better.
Important stats: Triton vs Crock: They are almost identical on all points except armor.
Preferred side: ARM
Bulldog and Reaper

Use: Heavy tanks is seldomly used since they cant hit anything that is faster than themselves. Statistically theyre very good but their weapon velocity is pathethic. The best use for them is too use them as a bigger version of medium tanks, to kick away DTs and stationary defenses. All units that have a slow weapon velocity is good in groups and that goes for heavy tanks also. If anything come close to them one of them will surely hit the intruder and they are so heavy so they can take some punches from each other(which doesnt go for leveler!). One thing to notice about heavy tanks is that they can dive quite deep...might be useful on some maps!
Important stats: Bulldog vs Reaper: Believe it or not, the CORE opposite is faster than the ARM one! In a you-shot-me-i-shoot-you duel the bulldog would win with about 0.01 second... but the reaper is a bit faster.
Preferred side: CORE
Goliath

Use: Due to the goliaths AOE its uses increase a lot. It can kick away DTs like debris and they can hit running flashes. The more goliaths the bigger the chance they will everything in sight. They can even kick down brawlers if they get 5 kills, or if they are very lucky. Enough goliaths backed up with AA is unstoppable. There are no defenses that can fend off them, except the tactic i mentioned above with assault tanks. Due to their incredibly low build time, your opponent can only crank out 2 flash when you get a goliath out, they will crush your opponent easily if he havent outmanaged you in the resource war(you cant feed this baby without a shitload of metal).
Important stats: Goliath vs Heavy tanks If you can pay for the enourmous strain a goliath give the goliath is big times better than heavy tanks. It wont move very fast though it accelerates faster than heavy tanks. Their great range makes HLTs almost ineffective against them also. But what makes goliath so much better than heavy tanks is the fact that it has lower build time.
Preferred side: CORE