From what I've gathered there isn't a whole range of different MA drivers available. The Grado GR10 is rated at 116dB / 32ohms which is pretty much the same as the e-Q7. So I think these too are quite likely sharing the same driver. 40 vs. 31ohms for the e-Q5 vs. e-Q7 is a significant difference (at least on paper), still my ears tell me these two have far more similarities than differences.
And yes, tolerance is really quoted at 25% on both spec sheets.