Tank + ranged always wins vs AI?

Not even because you want to try some new and challenging way to beat the game?

He has a point though. I think the biggest problem here is that the AI can't adapt and deal with it (or do the same), a lesser problem is that the strategy is a bit too effective.

I gave some suggestions for AI such as being able to pull off tanks to attack squishies, but Frogboy didn't want to implement them yet.  He could implement them if he wanted and things may well change.

Also AI STILL goes for the weakest army unit first! While I attacked an AI city, its units all went for a weaker unit of mine and completely ignored my squad of quite strong pale riders who were engaged in leveling its sov. How stupid is that!

Yes, the AI should evaluate both squishyness and amount of damage a particular unit can do to various units of its own.  If a unit is squishy but can't do much damage, it should be a lower priority for the AI (but still should be gone after if the AI can't damage tougher units with their current army).

What difficulty level are you on? You're right that this is a great army composition, but if the AI has better tech, larger squads, or higher level, tanks + ranged guarantees nothing.

Also, if 1-2 of your tanks die every battle, the economic cost of this tactic adds up. Against high defense units ( Gilden in particular), archers have little stopping power.

Against mounted melee units, even staff-based ranged units may not get in their damage soon enough.  

Moreover, when I have defenseless ranged units, and I run across an enemy army with archers - they sometimes get shredded. 

If you're playing challenging or under, time to up the difficulty. 

If you want to increase difficulty, just go with auto resolving all the battles you have .

Technically Verga has the best army possible. 9 Calvary units with great axes, impulsive trait from city and train them with charge trait absolutely insane.

actually mauls(or sledges if you have the great hammers trait) are more powerful, especially if your opponent fields armies with lots of chain armor (extra strong vs cutting). by the time they are in full plate, pikes are probably the best weapons anyway.

Pikes will give you the strongest stack of doom, With Great axes you have a higher iniative than sledges so you will end up going before the AI if he has units with impulsive. You will kill a majority of his units, before he even gets to attack plus they have backswing. Not to mention Warlord trait makes fielding these armies of doom much easier. Plus i like Yithril's army passives like +1 HP per level, +10% HP and +20 Carry weight, veteran with the iniative traits, charge, impulsive i find them tearing through everything.

Either way Impulsive is insane.

The AI could be better about choosing targets, but I don't have a problem with some expensive defensive units being a considerable boon to your army's survivability.  Fully armored units costs tons of metal and loose initiative, and you have to weigh that against the strength of high initiative, high damage, low cost units which are really very good at taking out enemy armies.  You can do so much damage in the first round before the enemy even gets to act (particularly if you're using ranged units for your damage dealers where the enemy usually needs a few round to get to you) that in many cases "tanks" are just slowing you down.

Now against the heavy hitting neutral mobs (dragons, bosses) having some tanky trained units is great, but that's a specialized situation that really isn't central to the main focus of your armies which is killing faction armies.

A big stack of Wraith Warg Riders with charge worked well for me before. Add lucky as a nation trait for extra dodge and it should be very hard to hit your units. Plus you ought to be able to attack first most of the time before they can even get the +5 defensive bonus.

Completely agree. The AI needs to have a few more scenarios it can adapt to. I also agree with other posters below that the AI needs to evaluate which units to attack based on more advanced characteristics. One thing I look at (to great effect) is the defense to attack ratio * hp of a unit. If a unit does a lot of damage and has no defense and low HP, of course attack first. Also look at how strong your own armor is - if a unit does 5 damage and has no armor, but all your armor is heavy, ignore the unit.

AI can't deal with spamming the heal spell either. If a unit won't die because it's being healed at fast as it's damaged, attack the healer.

Finally, the AI still isn't perfect with ranged units. First move in every tactical battle should be to move all of your non-melee units to the very back row. Even one more turn before they can attack you can be the difference between life and death.

Beric-

what difficulty do you play?

Learn to use other tactics. Don't exploit the AI. If this is the only way you can win then your tactical thinking is "SHALLOW" to say the least. You're playing the MECHANICS of the game instead of trying out something NEW every game or battle.

I suggest creating some custom factions with the Archers trait, and then designing powerful units for the AI's use.  When I first played FE, I created a variety of factions made to exploit the "sit back and shoot" strategy you describe, which worked really well when the game first came out.  Following the latest round of patches however, the AI is much better at building armies with many ranged units, and it's pretty merciless when it comes to tearing apart your weakest soldiers.  The reason you'll want to create some custom factions for the AI is that only 7 of the default leaders can even build ranged units, and of them only Tarth is particularly well-suited for it.  An AI faction with something like Lucky, Archers, Wanderers (for the more powerful leather armor), and one other martial trait should produce armies which will force you to try some new tactics.