I don't know why, but I hate doing Chrom x Sumia. I just don't. I did Sumia on my first ever playthrough, and I like her. Brady gets everything he needs from Maribelle, and I personally do Henry x Maribelle. Sully gets Donnel, Tharja gets Gaius, and Nowi gets Kellam because of Manakete wall. I may do Cordelia, because she is my waifu.