I'm not too bothered about Castor's bow, to be honest. I'll still get the fodder I need/want and build him. And, interestingly enough, he's a Red unit, not a Colorless one. I guess they figured between Jeorge, Gordin, and Norne, they had the Colorless areas covered for bow units.
Another option they could have used here in place of Yulia is Marisha. She's at least connected to Caeda and Marth through her supports with Caeda about Marth's relationship status. It's a loose connection, but a connection nonetheless. And Marisha isn't needed for a 7th Platoon banner, they have several options for that already: Cecil as the new lady on the block, an alt of Katarina, an alt of Male Kris, and/or an alt of Female Kris, plus an OC if they deem it so. A 7th Platoon banner only needs to carry Ryan and Arran, any two of Cecil/Katarina/a Kris/an OC can do that easily without Marisha.