Originally Posted by Bill Kapaun

Looking at the tech specs for both, they appear to be identical RE: ring sizes/tooth count difference/seat tube angle.

You might actually have better luck with a FDER designed for 1-2 fewer "speeds" if you have one in the parts bin to try.
I use a Tourney on my 9 speed triple "aberrations" and they work reasonably well for 22-32-36/38 combos.
It's a different ball of wax, but I had more rub with a 9 speed RDER.