If Riku seemed more satisfied with the idea of shooting WITH the Prince rather than watching him, while Richard was confused, Riku had a perfectly logical reason - practicing archery with Sora was perfect for flirting with him. He needed far less hands on help when not practicing with Sora.
Richard nodded in agreement with the Prince's suggestion of Roxas. He was suitable - no one would expect him to go easy on the Prince - and in height, age, and experience, they appeared evenly matched.
"I remember seeing the two of them at a council meeting." The one, in fact, where the Prince proposed that new law. "He had a ... rather sour expression about him. Hopefully married life has improved his disposition."
Riku doubted it, but there was hope, right? "Most certainly make sure that Lord Weller competes in something," Riku encouraged. "I believe at least one young lady would offer him her token." As for the Master Teacher, "I do think Master Zexion would be amazing to watch fight... the kind of black horse you never expect to pull ahead. As long," he grinned, "As it is not a mounted event. He does not do so well with horses."