Please pardon the double post
I want to point out to Antioch that I'm not trying to tell you you're wrong about trolls being tricky for a supposedly easy race. I know how annoying it is when an experienced player tells you "Nope your observations are wrong and you are playing wrong and everything is the opposite of what it seems". I used to have the same opinion as you, but after playing a lot of trolls I think the midgame slump is overblown, and can largely be mitigated.
I just think that the weird troll power curve makes it feel worse than it is, and also lures you into making it even worse. Most characters start kind of weak, and slowly feel more in control as the game goes on.
Trolls start off outrageously powerful. You can pretty safely o-tab your way to the temple without even thinking. Your skilling choices early on really aren't going to hurt you, no matter what, because you're so damn strong, that regen is insane early on, and the +3 ac is actually still meaningful. However the regen becomes less meaningful (although still really nice) as your HP pool increases. 3 ac is worth less and less as time goes on.
This lets you make a lot of mistakes without realizing. You could get to lair without training any defenses pretty easily. And the aptitudes make it look like a big waste of XP to try to train defenses. But then you fight your first spiny frog and it's a roll of the dice whether you kill it in one hit or it murders you in a couple rounds, because suddenly raw offense and a big HP pool aren't dependable enough when you're dealing with such heavy hitters that you can't just walk away from and regen.
However, as I tried to illustrate with that character dump, if you focus from the beginning on defenses (especially a shield, it makes such a difference) you end up with a not-too-squishy character in midgame, and you still have that outrageous offense. No matter what, a troll is offensively focused, and they're going to feel a bit more flimsy than a minotaur or gargoyle, with the upside of killing stuff really fast.
The other problem with trolls, as I think my character shows pretty well, is that you feel like you're steamrolling so hard it's easy to go on autopilot and end up not paying attention when suddenly you hit a situation that requires a little strategy. That's partly just due to the crazy offense, and partly due to the fact that there's a dip in the power curve that most races don't experience. I think even at the point of that dip you're still more powerful than the average character, it's just that you're in a completely different mindset.
So TLDR; Yes, trolls are tricky, but I believe the easy category is where they belong, but their fundamental design is different enough from the other races that it's not immediately intuitive how they can be 'easy'.
Also, just for fun, I tried another troll. Went with monk this time hoping to end up with a statue form troll (This is silly, if you just want to win a troll pick fighter). Mindlessly o-tabbed my way to d9, hit an out of depth manticore, and ran into until I was dead.
Cripes... I need to stick with tab instead of bumping monsters. The 50% HP warning probably would have saved me here...
5268 damiac the Grappler (level 10, -4/98 HPs)
Began as a Troll Monk on Oct 2, 2017.
Was a High Priest of Okawaru.
Slain by a manticore (22 damage)
... on level 9 of the Dungeon on Oct 3, 2017.
The game lasted 00:27:44 (7246 turns).
damiac the Grappler (Troll Monk) Turns: 7246, Time: 00:27:45
Health: -4/98 AC: 9 Str: 21 XL: 10 Next: 36%
Magic: 11/11 EV: 13 Int: 6 God: Okawaru [*****.]
Gold: 736 SH: 0 Dex: 15 Spells: 9/9 levels left
rFire . . . SeeInvis + - Unarmed
rCold . . . Gourm + (no shield)
rNeg . . . Faith + a - +1 robe
rPois . Spirit . (helmet restricted)
rElec . Reflect . d - +2 cloak
rCorr . Harm . (gloves unavailable)
MR ..... (boots unavailable)
Stlth ++........ S - amulet of faith
HPRegen 0.66/turn (no ring)
MPRegen 0.12/turn n - ring of see invisible
@: no status effects
A: unfitting armour, claws 3, fast metabolism 3, gourmand, regeneration 1,
shaggy fur 1, tough skin 2
a: Heroism, Finesse, Renounce Religion
You were on level 9 of the Dungeon.
You worshipped Okawaru.
Okawaru was extremely pleased with you.
You were completely stuffed.
You visited 2 branches of the dungeon, and saw 10 of its levels.
You also visited: Ossuary.
You collected 736 gold pieces.
Inventory:
Missiles
c - 220 stones (quivered)
D - a throwing net
J - 2 needles of confusion
O - 4 poisoned tomahawks
P - 2 tomahawks
Q - 3 tomahawks of returning
Armour
a - a +1 robe (worn)
d - a +2 cloak (worn)
Jewellery
n - a ring of see invisible (right claw)
S - an amulet of faith (around neck)
Wands
x - a wand of polymorph (12/24)
A - a wand of lightning (6/15)
E - a wand of acid (8/15)
G - a wand of clouds (5/9)
M - a wand of digging (21/24)
Scrolls
g - 3 scrolls of enchant weapon
i - 5 scrolls of enchant armour
l - 3 scrolls of teleportation
r - 2 scrolls of recharging
y - 2 scrolls of fog
C - 4 scrolls of remove curse
F - a scroll of torment {unknown}
K - a scroll of brand weapon {unknown}
R - a scroll of summoning {unknown}
T - a scroll of fear {unknown}
U - a scroll of identify
Potions
e - 2 potions of agility {unknown}
f - 3 potions of might
h - 2 potions of invisibility {unknown}
m - a potion of flight {unknown}
o - 2 potions of curing
p - a potion of berserk rage {unknown}
q - 2 potions of resistance
s - a potion of cancellation {unknown}
t - 4 potions of magic
u - 7 potions of heal wounds
v - 2 potions of haste
w - 5 potions of lignification
H - a potion of brilliance {unknown}
I - a potion of degeneration {unknown}
Books
B - a book of Cantrips
Spells Type Level
a - Confusing Touch Hexes 1
b - Animate Skeleton Necromancy 1
c - Summon Small Mammal Summoning 1
d - Apportation Translocation 1
L - a book of Maledictions
Spells Type Level
a - Corona Hexes 1
b - Ensorcelled Hibernation Hexes/Ice 2
c - Confuse Hexes 3
d - Tukima's Dance Hexes 3
e - Dazzling Spray Conjuration/Hexes 3
Comestibles
b - 13 bread rations
j - 7 royal jellies
k - 4 fruits
z - 2 meat rations
N - 6 chunks of flesh
Skills:
+ Level 6.0 Fighting
+ Level 5.9 Throwing
+ Level 6.0 Dodging
- Level 1.0 Stealth
* Level 9.9 Unarmed Combat
+ Level 3.9 Invocations
Here's just the highlight of me being dumb... again...
The manticore bites you!!
The manticore claws you but does no damage.
The manticore closely misses you.
You claw the manticore!
The manticore is moderately wounded.
You barely miss the manticore.
The manticore is moderately wounded.
The manticore misses you.
The manticore claws you but does no damage.
The manticore closely misses you.
You claw the manticore!
The manticore is severely wounded.
The manticore bites you! The manticore claws you!
* * * LOW HITPOINT WARNING * * *
The manticore claws you!
* * * LOW HITPOINT WARNING * * *
You claw the manticore!(Oh look, I'm almost dead at this point. Clearly the ideal solution is KEEP ATTACKING!!!)
The manticore is almost dead.
The manticore bites you!!
You die...(guess not)
The correct response to this situation would have been to turn around the moment I saw the manticore. Of course, if this was a Troll Fighter with a shield I probably could have won this... but still, it's a stupid thing to do.