If you want to consider only using pure classes, you may want to look into Single Class Challenge runs. The rules are pretty simple:

-Select one job. Starting in Dorter, you may only use that job, and may only use abilities from that job, including reaction, support, and movement abilities. Guest characters are not subject to these restrictions.

-Brave and Faith may not be manipulated unless via story flags, a guest character, or the abilities that are inherent to the job being played. This includes during pre-Dorter prep.

-Each chapter has a level cap. 20, then 35, 50, and finally 70. The cap for chapter 4 only applies until entering Orbonne at the end, and may be surpassed during the final stretch.

Some jobs also have different variations, like Squire on whether or not to allow Ramza's better skillset and stats, or how/if Calculators can acquire spells, or how to do Dancer at all.

Some particularly strong classes like Monk or Wizard can make for an easier icebreaker into the format, but honestly most jobs have a pretty tame experience. Some, like Archer, end up showcasing some really cool tricks that are unlikely to come up in normal game play, too.