Oh no I think Galio's great for Demacia as a relic of an old era; a representation of older Demacian traditions that perhaps were left to the wayside for whatever reason. He's an example of what Demacia perhaps did with magic in a certain capacity that they don't do anymore, and he also serves as great dichotomy to Sion as the construct with a heart and soul compared to the man who's merely a weapon. It's also a cool bit of internal dichotomy for Demacia, as Galio defends the land with as much effort as any soldier would, but is not only a being of magic but also perhaps not so bound to their dogmatic traditions; he does what they do as well as they can do it while also being a bit more lenient comparatively to the modern national ideology.
Poppy's got a quest to go on while Galio's got a land to defend. I've always liked the idea that the two have been friends for centuries and occasionally bump in to each other, perhaps days, weeks, months or years having passed, but being immortal, ageless beings the moment they see each other it's as if they were never apart.
I could go on about this but basically I think they can beef up Galio and still make it impactful for him to have failed protecting Durand, while also keeping his ties to Demacia as a relic of their older ways that still fights for their beliefs. Just thoughts of mine.