I have the guide, and it is from what I can tell partially unique. It's the only Rockman guide I think I have made by that publishing group, perhaps the only one they've made, I'm not sure.
To be sure, it's not uncommon for Rockman guides to have drawn stage maps rather than screenshot ones. Or for them to include short cartoons in them. But these are usually in manga form, either joke-oriented yonkomas (4-panels) or slightly longer more traditional comics that tell a shortened version of the game story, and not often integrated into the maps themselves. It's also not uncommon for a guide to present its own in-house artwork, often as chapter breaks, in addition to official artwork. I think Nintendo Power did quite a bit of that during the early 90s. This particular X3 guide uses a lot of both official artwork and their own, a very rich and colorful guide. I guess it's too bad there aren't more like it, really. But yes, much of Zero's color details (and X's eyes) are off. For the style, it works, though.
Edit: Actually, I did find 2 other books I had by the same publisher (though with some different talent working on the books themselves), for R&F and Soccer. I should have looked harder at more than just my X shelf. But, either of the other guides lacks the unique artwork examples above. The Soccer one has a few B&W yonkomas though.The R&F guide uses all Capcom art, save perhaps backdrops and such.