For smn/sch the shared base class caused sever balancing issues, and FF14 borrows a lot of lore from the Ivalice Alliance games with the flare of Irvine and "the man with a machinegun" from FF8
https://finalfantasy.fandom.com/wiki...nist_(Tactics)
And, most of these job split suggestions are usually just unimaginative pigeon-holding or like really boring like "pure-healer" is