Legend of Zagor was OK. It was ruined by the fact that one of the characters (the Dwarf, I think) could never legally finish the game because he will never get the magic weapon tailored for him as it is hidden behind a creature that requires a magic weapon to defeat. Sort of a catch 22 situation there.
The hellhorn champion does not require a magic weapon to defeat, IIRC. However, the dwarf does seem to get the short end of the stick. The fighter gets +2 armour and a +2 weapon, in addition to rolling 1d6+6 for his skill. Stubble gets just 1d6+5, and only +1 armour, meaning he is 2 points of skill behind. It is also odd that his stamina is generated in the same way as Braxus (2d6+12), when you consider that dwarves are supposedly famed for their toughness. He is the weakest of all 3 fighters, with no noteworthy ability to compensate.
It is funny though. Some sites I visited claimed that the wizard was far too weak to play properly, yet he was fairly powerful when I played him. The trick is that you ideally should have already played through the book once, so you know what fights to avoid and how to pace your spellcasting properly. Your magic is automatically replenished to 9 when you get the the wand of the hawk fairly early on in the game, and the effective +3 attack strength it grants makes up for its weaker skill. This means that you have little problem ensuring your spells go through (the orc battle was a joke, with the lavasphere and dancing sword making short work of most of the orcs, and a timely death spell KO'ing Thuul. In fact, I was consistently able to instantly kill any foe with skill of 9 or less using death spell.
I also got the cloak from the elf (used the genie bottle to disable him), so my wizard was never in any real danger in combat. And if need be, I can cast skill on myself as well. Magic rings are fairly plentiful in the game, and if you are very lucky, you get another way of replenishing your magic (neckerchief of wizardry). So you actually have about 36-45 magic points to burn through in the game!
The only fiasco I thought problematic was that it is possible to get 10 silver daggers in the game, meaning that Zagor dies immediately when you face him (though you won't know this until you face him in battle). I think the author was assuming an even distribution of daggers and talismans, but in one of my games, I did end up rolling all even numbers and acquiring 12 silver daggers!
Crimson tide was problematic because the silkworm had a skill of 12, while your own skill was just 1d6, so it is pretty much a TPK (the author said that its skill should have been only 6 instead). The final part had me stumped as well. Is there supposed to be some hint to unmask the traitor? I read every chapter but could not find any clue.
Lone wolf's only shortcoming was the sommersword. With it, most fights were a joke, and a few fights were nigh-impossible to win (chaos beast, kimah). It was ridiculous when I realized that the solution was to stack combat skill-boosting items from all the previous issues (including the distilled alether from book3), and still you came up slightly short.