That really is applicable advice from my point of view as a bit of a training provider too. Squarely in the tools/software category, where the tools in my case are electronic. One thing to think about is, even if "everyone" is going to use a particular tool, not everyone is going to use it ideally no matter what, regardless of whether their need is strongest or not either :\
I'm working independently part-time after retiring, but in my field I am more experienced than the vendor on a few of their devices and the niche software they offer alongside.
The manufacturer actually pays pretty good so their senior people retired earlier than me, leaving me in a decent position. Which I am just starting to take more advantage of. People have been wanting me to really come out of retirement and visit more industrial sites and I know that I can put places through the roof most effectively customized, where so many key things can be tailored to the specific client in their unique environment.
I can also do introductory stuff but others can do that too, and this is what the factory concentrates on, how to use their equipment & software itself which they really know best. For me to take it to the next level I am focused on the handful of industries which utilize that specialized hardware & software, where I have decades more of deeper application leadership than both the client as well as the manufacturer of the electronics & software.
The symbiotic situation is that I don't have to master all the equipment that the manufacturer deploys, just the portion that applies to me & my clients. And the manufacturer doesn't have to master every niche that all their different customers are working in, they're not without world-class expertise, but just enough to get in the door and you take it from there. The factory cannot thrive without much broader support abilities, but that limits the depth they can go even with resources that dwarf mine as a consultant.
Anyway I'm developing my own quick version of the basics, mainly to make the factory material more clear to my type industrial and research clients, and support the way I concentrate on deploying my most advanced offerings. I do need to be able to take students from "nothing" to "something" in one session in case they missed factory installation day where the factory engineer conducts the unboxing and OOBE on site. Then it's only a few more sessions to really get things visibly better, but somebody, at least one person, must be doing dozens of hours of "homework" between sessions or there's no way for them to get the most out of it. I'll be doing plenty homework on my own as I customize modules in advance of the next on-site session, and things must be capable of deploying directly to "production" each time. In this case high-stakes industrial production.
I'm about to take on a bigger client and raise my rates which should put me in a position to get better comp in case I do want to consider working directly for the factory instead of staying independent for a while. Either way the best I have to offer is things that others don't have, only some of it is actually more "advanced". But it's all progress for the client. Compared to alternatives having dis-similar backgrounds, I don't have all their unique strengths either so you want the integration to be a favorable one.
A general guideline might be that your "personal trainer" would be qualified to work either independently or as part of the vendor's team.
Also may be best to strongly consider first having the factory generic training for more students than will go all the way with it, especially if it can be done per-session without being invoiced per-student. Then take the few having the highest-aptitude and enthusiasm and turn the consultant loose on them to get to the next level on more of a one-on-one basis.
A lot of good stuff is one-on-one and it may be on your feet the whole time, but procedurally it's also often "OK" to have a half dozen participants following around soaking up everything at the same time instead of one or two key individuals. Yes, you can get more variety of pertinent questions in real time, but afterward the more people who were involved, then the greater likelihood that all of them will slack off on the most advanced concepts, thinking that one of the others must surely be more clear so they could relax a bit on that. More individual responsibility needs to be taken for the higher-dollar training, so the participants in that need to "take ownership" and be in a position to leverage it to their advantage for it to pay off the most.