One thing I wrote was that Funk Syndicate should buy a new mixer. This would have been good advice had my version of reality been the right one. David clarified that their mixer can reorder inputs -- the reason their input list seemed "out of order" was because of "ergonomics on the [mixer] and the money channels since some of our preamps are better than others at the moment. A lot of the channel moving is all of the relabeling more that the capabilities of the mixer." In short, they could have changed the channel order but it takes time to relabel their mixer and their outboard gear. (I am also guessing that by ergonomics they mean that they wanted the important stuff on one "page" of their mixer, which only has 16 physical faders, but at least 32 physical inputs). Makes perfect sense.
Still, it presents a problem for the FoH mixer who isn't used to finding most vocals at one end of the mix and one lonely vocal at the other. Confound that with something that I am guessing happened: Funk Syndicate sent their stage plot and Input List to the venue explained everything, including their unusual input list, the venue said it would be no problem, but failed to communicate it to the mix engineer in advance and the mix engineer got caught by surprise but Funk Syndicate thought he knew what the deal was going to be. I'm just guessing, but that kind of thing happens all the time.
I don't have a great solution to the issue without actually seeing the whole rig, and knowing all the concerns, but here's what I suggested to David:
If it were me, the first thing I would consider would be simplifying the rig -- sometimes less is more. Personally, I have never heard the difference between high quality and very high quality preamps in a live situation, but you guys might be hearing it -- especially with in-ears, or if the preamps are actually full channel strips or you've got other outboard. Or just give in and lose a little of that on your money channels. Labeling can also be an issue. You could try two colors of sharpie (one for each setup).
I don't know if this is workable -- every band is different and sometimes it can be difficult, emotionally, to have spent a hard-earned cash on high-end gear and not use it because it doesn't fit ergonomically into the rig. Something else to consider might be to give your venue two input list options, and let them choose. This could backfire because you are giving them choices they are not used to, so you'd have to find a concise way to explain the difference. You'd also want to be able to switch between them easily, preferably on site because the odds of the venue actually passing the question on to the FoH engineer and getting back to you with his or her answer is small.
Well, David has a tricky situation, no doubt, and I'm not sure I've done much to solve the problem because there is no easy answer. If you find yourself in a similar situation, remember to be as communicative, open and clear as you can be and remember to anticipate problems and be ready for them. A weird input list is one potential problem, so if you have a good reason for not following the usual rules, make sure to communicate those reasons, and, if you can, have a backup plan!