Generally speaking, yes, Sigmarines fit on 32mm bases. I did that with a converted Knight Questor, so you can see for yourself if it's for you or if you think it's silly. She's the female from Shadespire and has a wide stance, so is fairly representative of how much space a lot of the models from the range take up. I don't know if every model on foot fits, but even the Incantor from Soul Wars with her wide X pose can fit on a 32mm base, so you should be good.
I compared a hammer boy and an Intercessor that have a similar pose, and they're the same height.
GW seems to use the same proportions and dimensions for Sigmarines and Primaris.