Clay, I think all the hands-on people would agree that if you accepted a service life of 20 hours for a 1942 wankel, the engine would be quite plausible.
If you used the engine, as I pointed out above, for only 30 minutes a sortie, that's 40 sorties. (That is being generous, by the way. I suspect you would need to use the 'Wankel boost' for only 15 minutes total on the average sortie)
Most WW II fighter aircraft were dead anyway after 40 sorties. That's why Germany and other nations had to produce 1-2000 fighter planes a month just to keep their fighter numbers from going down!
So in practical combat terms, the short life of a Wankel is no problem at all.