Yes, I do, because of:

1) Variety. All mages all the time is boring.

2) RP reasons. Some champs just don't seem suitable as mages, e.g. Lord Markin.

3) Traits and abilities. Some champs seem more suitable for non-mage professions.

4) Itemization. It's nice to have a variety of hero types so all your great gear gets put to good use.

5) Resources. Too many mages can be too much of strain on the mana pool in some cases. Too many melee champs can be too much of a strain on the gold reserves (i.e. due to buying armor and other equipment) in other cases.

6) Fun. I find it fun to experiment with classes, abilities and strategies I've not used before, even if they may be under-powered or sub-optimal. In fact, winning with these strategies can be very satisfying for me.

There are actually a few ranged weapons that do not have an initiative penalty.  The Haunter's Staff was converted to a ranged weapon but no initiative penalty was added.  There's another staff that was converted, too.  And there were a few ranged weapons that didn't have them before, either.  Although, all of them come from questing and killing monsters.

If I'm trying to level a low-level champion, I'll put it with some strong units and give it a ranged weapon so it can contribute but stay out of the fire. 

I generally prefer commander for my sovereign. The early unrest bonus is nice, and the command skills is crazy useful.  There used to be a way to get battle crsurreally early as well by takin some army initiative trait.  Dunno if they fixed that, it was a bit broken.  Battle cry is really tricky to use right though.  When it works it's ridiculous, when the timing is off...it's ok.  Initiative traits are crazy good though.  Withthe right build you can guarantee your troops win knit every time, then combine that with finesse you get a cheap and effective attack boost. 

I don't really like the research or Gildar bonuses.  They are ok if you can ge them really early, but late game they are pretty meh.  I play epic scale research though so that could be part of the problem.  They should probably scale the research bonus a bit.

I guess mages are still more powerful though,  I've just never been able to sort out the spells.

So I'm playing my first game with a serious assassin, and I have to say I am very likely to play this again.  My god the buret damage from this thing is incredible. It helps that I found a druss blade and Pony, but still.

The main thing is that mages and commanders are far less dependent on equipped items compared to the other classes, they employ their benefits naturally without the need of combining them with what they wear. Assassins, Warriors and Defenders can be as powerful or even more important in certain situations IF they find the appropriate equipment:

You find a rare/unique bow and suddenly your assassin has become a killing machine combined with the ignore defence and critical damage traits.

You find a rare/unique armor and your defender can withstand basically every kind of damage combined with his damage/spell mitigation traits.

You find a rare/unique melee weapon and your warrior will have the highest damage output on regular troops in the entire game combined with decimate and other traits.

In addition, only if you have the right equipment all the different class specializations come into play so that the assassin will be a champion killer, the warrior will be the trained troop killer and the defender will protect your army from Fear and other spell/damage effects. The problem is not the trait trees, it's your forced reliance on luck concerning what loot you find. This needs to be addressed.

Great advice. And interesting to read that a 3 magic schools Sovereign Assassin can also be an effective caster.

Stormwatch27's post opened up an even more interesting option. 3 magic schools plus Commander will suit my preferences and playstyle perfectly. As I'm new to the game, I've only used one of the the mage's talents; Healing +50% and put the majority of points in increased Life, Air and Earth - something I can do just as well with a Commander. I want my Sov to bolster the troops from behind - but still have access to Life and Air. Thanks for the idea.

1. Best of all are warriors if they can cast spells. Mana may be low. But they have always good attack.

2. Useful are wizards for additional spells.

3. Occasionally useful assasins, thargs are best with double strike, perhaps.

4. Very rarely useful, almost useless defenders and commanders. Defenders expected to buff whole armies, but they buff only themselves. Commanders are of doubdt specialization. They are specialised for city government and for battlefield which are mutually exclusive. AI plays weak with defenders and commanders.