Just going through the game for the 2nd time now, making sure I got the light sword in Bayjin - my god that thing rocks 
Next time I'm planning either the solo faerie ninja, or a six-fighter party (probably Liz/Mook/Dracon/Human/Dwarf/Felpurr). Which is harder? IF Wiz7 is anything to go by, the lone ninja will be pretty difficult till level 15 or so, and then slaughter anything with no problems. I imagine the Fighter party will have no trouble getting to Arnika, but don't like to think about what no spells or lock-picking means.
Sirtech knew Wiz 7 wasn't balanced very well, as Ninjas and monks maraud everything in their paths, and thus, changed it for Wiz 8. while a Faerie Ninja with CoC is still good, you do have quite a long, difficult road ahead. so many skills to work on ( staff and Wand, Close Combat, Dual Wield, Stealth, locks and Traps, and magic skills. with CoC's "feature", throwing and Sling, as well), it quickly becomes mindnumbing for weaker people, who can't give such time and effort into building a super character.with 6 fighters, you have tons of offense. the undocumented feature of Wiz 7, where fighters recieve double damage, has been removed in 8. Fighters also have Berserk available, and Stanima Regeneration (expect to be able to berserk all the time and never rest)
I'd say, TLN is harder, simply because Fighters can use the awesome weapons like Light Sword and Excaliber, and you don't have to worry about how to kill crock with 1 Fairy Ninja with pathetic weapons.