Demonspawn is Simple, Troll is intermediate
Troll is really not very good at all in the mid game on. There are chance based conditions but the species generally sucks and the aptitudes make it hard and annoying to play. Demonspawn can be utterly broken and when you get a full claws stacks the species is **far** superior to trolls in every single way.
There is not a single thing trolls can do better than Ds with claws. Trolls are worse than Naga in the late game and IMO a complete pain in the ass and "simple" should not be used as a way of saying it's the most chopped species in the game.
If you tell a new player to play TrBe because they're easy they're going to grow to hate the game because of how hard it is past the early game due to a slight possibility they're getting armor. There's only one way to play troll too and that's to charge in unarmored which is always wrong.
Here's my idea : Bring back Death Knight and put DsDK as a simple role. Ds^Yred is busted simple and straightforward and throwing players into the beginner role with backup and damnation is plainly superior than tossing them in as a glassy giant with a severe learning disability.
You can make a guide for a melee Ds,
Train fighting (asterix), train weapon/claws(asterix) train invo(+) and you enter simple difficulty with Yred. No complex skill arrangement required! Works into post S
Edit : good points. ITT simple intermediate advanced is more of a "how easy this class can be played" vs "overall power"