i am trying to figure out the best way to mesh together an rpg with a turn based strategy wargame. i am thinking something along the lines of Final Fantasy Tactics for the combat but with modern units (ie tanks, artillary, maybe even planes). however i am not sure how to apply rpg elements to these kind of units. maybe as they defeat more units they can equip better armor to their vehicles, operate more powerful weapons, etc... just not sure about that. another issue, lets say that the player operates like 5-10 units per battle, why would he not constantly select the tanks to do battle with, what is the motivation to select ground troops when a tank could prolly destroy them easily. i am just thinking the player could have his tank fire at a ground soldier (or group of them) and there is no reason why the soldier should still be alive.

You should really check out the Advance Wars games for the GBA/DS/GameCube.
They have an interesting take on handling this kind of stuff.

Another interesting thing is integrate Advanced Wars with gameplay similar to Bang Howdy

http://www.banghowdy.com/

I like how it's a type of almost real-time turn based RPG system. I think it would be interesting to see it more often in games.

Four words: Sword of the Samurai ( http://en.wikipedia.org/wiki/Sword_of_the_Samurai_(computer_game) )

I would consider this an RPG (you play the role of a Samurai lord who eventually tries to unite all of Japan and become Shogun. You have to consider yours and your families honour and manage your estates. You have to defend your territories from invading forces as well as conquer your neighbours.

It is an RPG with many sub games. Which includes a real time whole army battles (but they could just as well be turn based), but also includes a Turn based strategy (select which territories to conquer).