Greater Mummies and Liches are not exactly what I would term as 'normal' enemies, but in any case, PfUndead Scrolls.
Dragons are scary in melee yes, but they spend the first few rounds casting spells. A Warrior can down a Dragon in two rounds, barring certain ToB ones which require a bit more tactics( but still doable, although you need a lot of potions and scrolls).
Mind Flayers are problematic I will agree, and a solo Warrior will be hard-pressed to defeat them easily, but in any case, Greater Deathblow( ToB HLA).
It will instant kill even the Improved Mind Flayers, and it ignores their magic resistance too. A highly under-appreciated HLA. Works against Beholders too!
Too much hype for Critical Hit and Greater Whirlwind.