How to make game-ready topology for meshes like that?

I've studied today how to make retopology from HP to LP, but approach which author ideally fit flat surfaces. I've understood that and used it, but when I met this, don't really know what to do. Maybe someone can help me and give advice how to make game-ready topology for curve meshes like this

https://preview.redd.it/mtqmbabrn55h1.png?width=2559&format=png&auto=webp&s=e03f2acefc2686a86f4052eee03a8021b9f2456a