My favorite rage skills - Stone wall from first one; Evil shoal early on from second, and only glot's armor later; from third - chargers, ice orb, and ice thorns; from reaper - time back, and sometimes soul and rage draining, but time back is essential later.
I used 4 shooting units(1 being inquisitors - for resurrection and 1 archmages - for shields) + 1 tanking/melee most of the time.
Tanking was Horsemen and later Archdemons when i got tolerance, but my guess is that anyone could work.
I had telescopic sight (got it after I married the dwarf, and i did marry her only to get it, then dumped her for the frog, and stuck with frog till the end, I just happened to have nice artifacts, and 3 artifact slots = win).
First magic I developed to level 3 was distortion, and lvl 1 chaos and order.
BTW 1,7M gold is nothing I spent millions to get runes (bought like 8 magic ones :S)
Mostly used spells - haste; slow; target(!); gift + sacrifice; magic spring, stoneskin, peacefulness, battle cry.
Basic tactics is make them hit your tank
Target spell helps a lot if there are many range units.
Do not buff the tank on the first turn unless the enemy is very strong; Use time back on it at the end of the second turn, and then buff it with mages and a spell; Use time back on tank each time it charges up. Leave one enemy unit unkilled (as much weakened as possible) and drop an ice orb near it to prolong the battle, then use chargers/rage draining/time back/gift/resurrect/holy anger to recover as many loses as possible.