Now the problem is making people fly the right ships, newer players excluded.
Never try to MAKE RvBers do anything - believe me they push back hard. Remember you have people here who came here to GET AWAY from being told what to fly & when.
You have to lead with the carrot, not the stick
For example DONT make a fleet that simply says "VEXOR FLEET, only this stuff allowed", and expect people to join right away. Give them some notice - corp mail will be good with maybe a reminder on the day you want to do it the first time - and as part of that, say "first x people will get their ships for free".
Believe me it works.
If you are too poor to do that (and seriously anyone intelligent enough to FC should NEVER be poor for long), then the usual "bring your own stuff like I want, get kills, best killer in this fleet gets a prize" (even a faction frig is good enough) can often do the trick. Doesnt have to be that way everytime, but as an incentive for early attempts.
Hell, the only reason talwars worked in the BNI war was I provided hundreds of the bloody things, plus every support frig I wanted with the setup. Sometimes you just got to do it that way, provide all the tools to make a setup work the first couple of times (especially if its in a war with a group in a terrible market area as we arent letting the locals restock as we keep killing them ) without having to wait while people go buy stuff (I get impatient easily).
If you do not want to do the above (prize or free stuff), then its all about how you word your mails, sugar over salt. Use persuasion - again something a good people handler/FC should have.
And then of course the biggest thing regarding doctrines in RvB, using them against the other side may very well cause drama if there isnt an FC willing to think about how to deal with it (those people should either learn or biomass). So yes you get a fleet to do something, but then do not actually get a fight.
I have found the best time to use them is in wars - the recent VoC war would have been a great time for doctrine minded FC's top break out the fits etc - as we have seen in EUNI/BNI etc People become much more willing to be organised into a unit instead of a mob when we purple up to kick someone in the face with our jackboots than when its kicking each other in the face with our beach sandals on.