I find this attitude silly, especially when the game is super easy, even on Maddening mode (aside from one map that is a real bisch). I find plenty of classes that are good aside from Wyvern/Pegasus. Dancer, Mage/Bishop/Dark Mage, Brawler, Thief, Brigand, Cavalier, Dark Knight are all viable classes. Even Armor Knight is useful for certain characters (at least in the early game). Plus converting certain characters to Wyvern takes A LOT of grinding, which should be a dissuasive for most of these shenanigans, unless you enjoy repetitive pointless battles (I sure don't).
sometimes, it's very necessary to either impose hard limits or incentives to make the player engage with the game in a way that makes it fun but challenging. give the player too much freedom, and they will do whatever they want.
when i play any game that allows the player to either make or recruit female characters; i almost exclusively go for a full female party or team. that was actually detrimental in tactics advance 2, since i couldn't dispatch characters to finish missions. lv 60 characters, failing missions; because they couldn't use the recommended job. and one mission i think requires you to dispatch at least one group to do it since you can't walk and do all three battles in the day limit.
in fire emblem three houses, when i learned that i could swap anyone to any job, my first thought was to go for a full paladin brigade. the only reason that i didn't was the fact that there would inevitably be a desert map somewhere in the game, and everyone having only 2 movement would make me hate that map. i know full well that the blame would lay with me, but i'll still be made at the game.
and with games like disgaea, the "open class' thing can render even unique characters irrelevant.
i barely use the main character of each game. i usually pick a few female classes and build my entire team form that.
the game has to make sure that the player is encouraged to make thoughtful decisions when creating characters, recruiting them, or selecting them for battle. your thoughts should be:
"hmm, grasslands, some forests and 2 rivers. lots of grunts with lances, 2 archers, 1 mage and the boss is a lv 3 general. 2 or 3 axe users should be good. the grunts are low level, and i got this new guy, ross; he seems promising, i'll add him in. i'll add one pegasus knight, 2 mages to gain some exp at the bottleneck areas on the map. hmm... erika is a little low on levels, i'll give her this iron sword and give her a few kills to power up on. -clap- alright, that set up looks good. let's get this started."
conversely, in a game where your starting characters don't matter in the grand scheme, where everyone can learn or equip anything, you won't think like that.
here are my thoughts when playing disgaea and checking to see what all classes are avalible:
"alright, got to get a cleric, she's hot like lulu, got heal spells; i'll reincarnate her or teach her the other magic spells later. give her a lance. [clerics don't specialize in lances], next, fight mistress, pink hair, pigtails, energetic, shows a bit of cleavage but not like the cleric. nullifies counter attacks, that's very helpful. pink hair mage girl, for fire spells, you get mjolnir, for shits and giggles. succubus, need a scantily clad demon girl with curves. turns into a gun, hmm... oh, the gunslinger; a busty weapon for a busty bespectacled cute babe, perfect. now, who are the dlc characters? okay, rozalin, and etna. perfect. okay, -scribbles notes- you unlock by doniig this, and you with this; okay now to get started."
see the difference? one series encourages thought planning and consideration, the other is "do whatever the fuck you want to, whenever you want".
