You may not have expected this response, but I think you may be missing an opportunity here. Bear with me.
Ask yourself why they’re depending on using their phones if there’s a dedicated shooter/editor available.
Is it because you’re spread too thin and aren’t as available as they need?
Is your turn-around time too slow?
Or is it that they are unaware of your services, or it’s too time-intensive to do something spur-of-the-moment with you?
Do they just not know what you can do?
Or do they just a very casual opinion of media and how it’s done?
Do they think phone video is “better”, i.e. more “legitimate” or “truthful” or otherwise valid, than using more traditional capture methods? ( I have to laugh here as I personally still don’t much care for using DSLR’s over dedicated camcorders but that’s a discussion for another day).
See, none of those problems will be solved just by taking more DSLR courses. Though of course, take some if you need them… No, there’s a different problem here and if you want to have good job security and advancement, pay attention to what their actions are telling you. They are choosing their phones over you. It is vital to your job you figure out why, and what you can do about that.
They’re shooting badly with their phones; you could turn this issue around, and give mini clinics or one on one tutoring or make a tutorial slide show or in-house video on how to do that better, and point them to things like proper apps for shooting from the phone, that control focus and iris and sound, stabilizer apps, etc. you could help them get cheap, even used tripods and mounts, and a shotgun or wired lav for the phones, those lavs are like 20 bucks but make a world of difference. And not coincidentally, they end up giving you better, easier raw material to work with.
There are various benefits to this approach that may not be immediately obvious. One of which is, you’ll be establishing, or re-establishing yourself, as *the* video authority, the guy everybody comes to, who makes their stuff better. You’re proving your value. You will make good personal connections to these people by mentoring them and making them look better and do better. You build trust with them; instead of looking at them as competition, you’re recruiting them. What you may find happens next from this approach is, even though you’ve given them the ability to work independently from you, and have better results, because they have grown an appreciation for what goes into good media, they will start handing off more things to you that they want “done right”, instead of doing everything themselves. On your end, you’ll have to be very fast on turn-around of their stuff, and always improve the look and sound of what they give you, any way you can. They give you crummy vertical video of a bust shot? Frame it to the side and add graphics and text to the rest of the frame, to make it look polished and intentional. Clean up their audio; you can’t believe how huge an issue this really is in making your stuff stand out from theirs.
Other people can give you better tutoring on the DSLR stuff. But realize you have something more urgent, more fundamental going on here and IMO you need to address that as a priority.