Since pillars has no element of attrition anymore all classes are very samey. All of them work by firing on all guns as soon as the battle starts, just the aforementioned casters fire a bit harder at first and then fall off more, the martials fire more consistently throughout the battle.
Old Wizardries are very attrition based.
Fighters are classes that suffer zero from attrition. They are at their most efficient just choosing the attack command, later sometimes berserk. They can't do anything outside of combat. They are gonna do all the heavylifting on generic random encounters, and level ups/more gear on them makes normal progression much much smoother.
Thieves have no attrition aswell, but they also have less direct combat utility than fighters. They disarm traps, open chests, lockpick doors, and generally make your progress through the dungeons more smooth. They are the attrittionless out of combat class.
Mages are the attrition combat class. If they use their spellslots they are trendemously influential, and will be generally the most important character in hard fights and bossfights. They have a few spells that work out of combat (and which generally makes them the most important class in the game in good old fashioned caster supremacy) but mostly they are the nuke you try to keep at full power throughout the dungeon, to burn down the boss with.
Cleric are the attrition out of combat class. They don't really cast that many spells in combat, throwing out a buff or two or a few healing spells if the battle really goes dire. But their spell slots are frequently drained throughout the dungeon, and if your Cleric can no longer heal you basically have to abandon your run.
This is the class balance of AD&D, and from those first four classes (three that is, as the rogue joined them later) there are the four general archetypes that a unit can have. Later Wizardries make things a bit more complicated with psionics and alchemy, but even at its most basic there are four big class fantasies which give Wizardry games their class distinctions.
Sawyers games on the other hand try to have as little class distinction as possible.
The distinction between the fighter and the rogue is the weakest in Wiz, since both just want to use their auto attack in combat.
I'd say even that distinction is bigger than the distinction between any two classes in the pillars games, even if you take the druid and the monk.
Sawyer's balance philosophy is so disdained since it takes the edge from things.
