Yes, both are Maruyama fish, mother Murata bloodline and father Kagura bloodline. Maruyama uses several pairings for their kohaku breeding, including Kamiya-Kagura.
My wife prefers the unique pattern on F1 but personally, I prefer F2 - its pattern would be fantastic on a big body. That is, if the fish performs.
Haven't had the chance to measure them yet, but in reality F2 is actually much smaller (I estimate 30cm) than F1 (I estimate 38cm) despite them coming from the same spawning. Having had them in my pond for a week now, I notice that F2 eats sinking food but not floating food. F1 eats both.
I hope F2's growth rate will catch up in due course. Its body structure is conducive for a big fish.