Skills in the game

I think everything is obvious:
You can take a hero with Logistics. If it's important to explore more of the map early on, and in the case of the Elves, it's a must – because Dendroids are powerful (I think you understand which hero I'm talking about).
If you're playing as the Necromancers, it's definitely Aislin, and not just because of "Meteor Shower." Aislin is given magic skills that are exactly what's needed.
For the Barbarians, everything is also obvious (Crag Hack, of course!).
If you're playing as the Elementals, I forgot the name, but the point is that magic should be a priority, and fire magic in particular.
For the Swamp, it's Stig... because Stig + Top Gear is a great combination. But seriously, there just aren't any other good heroes for the Swamp; it's impossible to level them up, and they get such useless skills.
For the Stronghold, I think everyone has a choice between Deemer and... that shaggy guy with "Resurrection." Although, again, if speed is important, Gunar is very good (if you don't choose him right away, you have to try hard to buy him).
For the Devils... I can't say anything about them. At one time, I played a couple of campaigns with them and a couple of 200-tile maps, but that was a long time ago, and I don't like their Castle.
Oh, I almost forgot about the Humans. They are the only race for which water magic is important because the Prayer spell on the Human army is powerful (and the choice is based on this).
That's my opinion, if anyone cares.