historically rockets were created for aviation. Then they were used on machines (Katyushas) and then used on boats of river flotillas. This is historically correct.
I propose to transfer the technology of missiles for firing at the ground to the Red Army in aviation, general research. After the passage of which the missiles will be available from fighters (I can paint on which fighters the missiles were not installed, this is a small list) from attack aircraft of the Il-2/10 family. Katyusha will become available.
Separately, I propose to introduce coastal (river) artillery boats with torpedo weapons from the Red Army. After studying the missiles, add missile firing to them. Boats are prohibited from going into deep water. this is historically more correct than giving the red army an aircraft carrier with the possibility of landing on it IL-2