inb4 "NOW THEY'LL HAVE HYDRA BEHIND THE SOVIETS TOO!"
Honestly, aside from some shyness about even partial glimpses of the Swastika in the film, it's abundantly clear that Hydra does not
replace the actual Nazis in CA:TFA, but split off from them. Hell, they're more or less a cross between the Ahnenerbe
and the Waffen-SS
, except less
cartoonishly evil and insane than either.
And as for Nazi Russians? That's happened in WWII, and it's not that far of a stretch to have Hydra work it's way into the Soviet underground, especially given every other anti-Soviet
group that existed.