Is there much difference in height between Midwinter fire and the red Dogwood? Google seems to put the red barked one as much taller. If that is the case I just need to switch positions in the bed.
the red one is much more robust and grows much quicker. Midwinter Fire will get fairly big eventually if not cut back but at a quarter of the speed of the red one (or even slower). You can't cut it back regularly and expect it to come back like the red ones.
I had both in my last garden and found they grew at about the same rate but the red one, being more sturdy and resilient, could be cut back hard every spring whereas the Midwinter Fire sulked if I took out more than a third to a half of the stems each year and you do need to keep cutting them to maintain the interesting stem colour.
We moved to this new garden in October and I will be getting more of the red because I love the strong red colour but not the Midwinter Fire because it suckered like ad once it was happy.
If you cut them back do they grow as big or does it take time?
If you cut back MF it won't grow as big as a red one, no. See what Obelixx said re cutting it back, you can't treat it like the red ones