This is also highly theoretical. If the machines are different enough, you can adapt quite well. Even if you have trouble telling other people exactly what to do, your brain doesn't have much trouble. I especially find it easier if I use different operating systems with keyboards that are somewhat different, because my brain has an easier time treating them differently when there are visual cues (since I'm not looking at the keyboard).

For instance, I have always though that cmd+X/C/V vs. ctrl+X/C/V would drive anyone nuts if they used them enough, and realistically most of the common Mac/Windows editors commands have exactly that one difference of ctrl vs. cmd, which is essentially pinky vs. thumb (at least for me) for the modifier key. It turns out that it is extremely rare for me to accidentally use the wrong one even though I usually use the same software in both environments, because my brain picks up on visual cues from the OS and the tactile differences between my keyboards.

Of course, coming from this mix of environments, I think they could have taken the cue from the MacBook and just kept the backspace key and removed the delete key (even though Apple wants to call it the delete key...), rather than bastardizing the key with that weird split key.