But not the Zowie EC1, EC2 eVo range, Logitech's range, Mionix 3200, 5000, 8200, DA2013, Naga, Mamba, ROCCAT Kone range, Saitek Cyborg RAT's, SteelSeries Rival, Ikari and heaps more that were made in the last few years.
Eh... I would disagree that a good chunk of those above mice are any adaptations whatsoever of the IME3.0. Just because it's right-handed, doesn't necessarily mean it's a derivative of the IME3.0 shape. But, I guess that's just a matter of opinion.
Like, the Naos, G400, G700, RAT, Naga, Roccat Kone, Rival, and Ikari? I'm pretty sure they are not derivatives of the IME3.0. That just leaves the Zowie EC1/EC2, and the Deathadder/Mamba as adaptations of the IME3.0. But that's just to my eyes.
And, yes indeed, there were right-handed mice before the IME3.0, like the IntelliMouse Pro you mentioned, and the Logitech Mouseman (the triangular one that I posted in one of my previous posts), but doesn't that mean the IME3.0 ISN'T necessarily the "founding" right-handed mouse?
It's absolutely possible that the Naos, G400, G700, RAT, Naga, Roccat Kone, Rival, and Ikari were developed from scratch, without any influence whatsoever of the IME3.0, given that there were other right-handed mice before the IME.