For an easier time with passives, i reccomend breeding a Yakumo first and condensing it to 4 stars! IVs don't matter. As soon as you got one with the passives you need, just catch the desired species you wanna breed while Yakumo is out and fighting. The caught ones will have a high chance to inherit some of the passives. So all your future breeding projects will be a lot easier. (You can't inherit special passives that way like legend, lucky or the special elemental boosts) For IVs you can aim simply for high values and give them the last push with the new IV fruits dropped in raids or sold by the medalmerchant. The increased IVs also work for breeding afterwards. So you can use these pals for chainbreeding. You can also look into inheriting active skills. Obviously that's only important for attacks, which canÄt be obtained by fruits.
What about the pals that seem to alwas spawn with Glutton such as Relaxasaurus? Does anyone know if you can breed that trait out? Esp since that's a "gateway pal" early game to breed for end game ones