Who were the first romantic partners intended for Callum and Rayla before the "lightning strike" story board changed direction?

I read about and watched the lightning strike story board and how the creators never intended to have Callum and Rayla get together romantically before then. After they saw the story board, they all decided that their relationship makes the most sense and created what I feel is the best relationship written for a modern animated series.

My question is what was the original direction for these two? The Dragon Prince seems to have plenty of well written LGBT and hetero relationships, so Callum and Rayla could've ended up with literally anyone or no one in a romantic way. I find it interesting that the excellently written relationship wasn't even pasti of the original direction.