Considering both those ogres are my characters, lemme give ya my two cents:

First one is a half-ogre, as I wanted to create an orc but orcs in this realm aren't greenskins. She's suppose to be a shaman like character and just happened to grow up mostly around human mages, so in this instance it's more of a lifestyle for her than her brand of ogres being magically inclined. If Ryla ever returned to her ogre clan she'd find that only the clan shaman has any interest/ability in magic, while everyone else is your average ogre.

Second one, as you said, is more of a magic eater than a mage herself. In this instance her thing about magic is more related to her specific clan of ogres rather than ogres in general, since I'd assume that there are many ogre clans around the world and each one have their own history and culture (Beyond violence and raping men of course). They hate magic because a sorcerer used magic to control them, and after they overthrew the mage they intentionally went out of their way to make sure something like that can't happen again. Not by studying magic and learning how it works, but just being immune to it so next time some wizard thinks he can try to get a clan of ogres as his servants, he'll just get clobbered for his troubles.

Now you may think Ogres can't do anything but rape and pillage, and I'll concede that there isn't really any evidence that they don't do anything but that. But at the same time everything evolves over time or else they die off; ogres may be naturally strong enough to break stones with their fists, but even they would pick up a weapon just to make the stone breaking easier. And sure they may be tougher than most mortals, but arrows hurt, so sometimes they will try to make armor. For Sheolred, her clan faced a similar thing but with magic instead of arrows, and magic resistance was their armor. For Ryla it's less because she's an ogre and more because she grew up among humans, and learned their human crafts. She just happened to be a half-ogre mostly to explain why I used a cute flat-chested orc girl as my character image.