the summoner summon system need a complete rework.
summoner need to be able to summon more primals like shiva,rammuh,leviathan not just ifrit,garuda,titan to make it feel more like a summoner rather then a simple pet controller.
i dont mean u have to use all but to be able to pick the ones u prefer which they fall under a certain category like dps,defence,support something like that and big summons like bahamut and phoenix need to be somewhat combo finisher in the higher levels.
also i believe they needs to make summoners rely on their summons more not just his debuffs and ruins since that is kinda the point of summoning.
i truly believe once they change how the summon works ,the potency numbers can then be balanced more easily and approriately among the debuffs and ruins and the summons skills as well.
it doesn't have to be the strongest dps but with better summon system that really utilize the summons better it will be fun and makes u feel more like a summoner rather then a sloppy pet class.