Define "MONK"
Define "BLACK MAGE"
Define "RANGER".
and you'll have a proper answer.
No! a lancer is not a DRAGOON.
A lancer is a set of skill with lance. what a lot of player is missing is:
the system is sandbox style, not themepark style.
There are not classes and roles well defined because the game it's not done for a single class, but for a set of skills.
They could do as Ultima online, where you had to macros a single skill, they have prefered create "boxes of skills"
Yesterday I was playing as Conjurer with shield skills, debuff from thau, healing and buffes from conjurer and interrupt from melee. It works, and it's fun.