If you have the skill, it is easy.
That's the biggest point, as long as your adventurer is not experienced enough by killing hundred of things to have high weapon/dodge/armor/shield skills, an encounter with boogeymen will only mean your character demise, as most of your attack will miss and most of their attack will hit, chip a bone and render you unconscious.
But that said, even a starting character can get extremely lucky sometime, i had an early df2014 mortally wounded by a bogeyman that suddenly thought it was a good idea to be a super warrior out of the blue.
By being very lucky has of course its limits, considering you are never fighting a single bogeyman (that is near impossible enough for starting characters) but multiple ones.
Now without counting on luck, in df2014 i had starting characters being able to survive 3 bogeyman using the multiattack exploit, that was the main way to deal with the overpowered df2014 undead too
- press the , key to wait for the enemy to be in contact
- press SHIFT+A to aim an attack
- press a to Strike
- select the bodypart you want to hit
- press z to enable "multiattack"
- select the type of attack you want to use (slash/stab/etc..)
- press SHIFT+A to aim a 2nd attack (thanks to multiattack)
- select the Dodge option instead of an actual attack
- Dodge in the direction you want
- Press . to launch the multiattack (the attack then the dodging)
You'll miss most attack, but will sometime hit, and your enemy will miss most of his attack that would have connected in normal fight
Can't say if it still works in 42.x , not playing adventure mode anymore.