Porkdish: Here is my 2nd time through party.
in the spoiler tag are screenshots of just my end game inventory, statistics and skill points. They aren't optimised to within an inch of their life, but the game was quite easy with them on hard difficulty.
I have tried variations on them since, improving damage and defence but its not really necessary to finish and enjoy the game.
You should always have a minotaur in your party, but more than one isn't the greatest notion. The headhunter perk makes them a stand out damage dealer, as either throwers/archers or melee fighters. I prefer them as unarmed or dagger rogues or dex sword fighters. They have great natural strength (plus the giant damage bonus from headhunter) but they need a big boost in accuracy.
You can get lizardman fighters in end game plate to ~80 armour with nearly 70 evasion (I wasted skill points in the above example). They're effective the entire game. Sword and dagger weapon types improve defence too since they boost dexterity and thus evasion, swords also have a parry milestone that adds 5 evasion. Invest highly enough in armor and shields double their evasion rating. I never had an evasion penalty in heavy armour, once I had the skill level to use it.
My back row rogue was just to test out assassination. Its not that great a skill, but its not exactly a handicap either. You're probably better off with a glass cannon strength rogue in the back throwing things or shooting arrows. They'll die if you get surrounded but for most of the game they're rapid fire death to any monster. A lot of parties use their headhunter minotaur for this role.
Magic isn't really a powerhouse in the game, its average direct damage and a couple of schools offer good utility effects. Having two mages isn't exactly impractical, but its not the secret to ultimate power or anything.
There's no hard evidence that prioritising one school equals more spell damage, though that is true of weapon skills, but its not a good idea to spend points in more than two mage schools just because there aren't enough skill points to reach skill milestones. If you do go with two mages then its best to pick complementary schools on each like ice on one guy, and earth on another to poison enemies while they're frozen.
Don't stress out on some poorly spent points, you don't need a perfect party to make it to the end.
Picked up LoG the other day, cuz I was feeling a bit nostalgic for EoB. Played through the first level just to get a feel for the game with the default party, and I am now going to build a custom party for my first playthrough. Just want to thank you for posting, as it gave me some nice insight as to what type of party I am going to put together, to brawl my way out to freedom! :)
