God save us all from having to bring along greenies!! We feel your pain. I vote rude too. I vote looking out for #1 first everytime. I have a STRONG sense of self preservation so I'm not afraid to speak up but I find self deprecation works nice. Kind of a passive/aggressive way to getting outa the predicament!!
EX; Say something like....I'm sorry but I'm a bit scared of my horses reaction to this pace and think I'm going to pull out and go it alone. I'm a weeny and want my green horse to have a good experience and stay calm. I'd LOVE for ya'll to help me but I don't wanna ruin your ride either. Would anyone like to join me for just a quiet walk out here today? Otherwise ya'll go on and if you don't mind; could you move off slowly.?
It's all about communication too. We can't blame others if they can't read our minds. You gotta TELL them how you feel and what you want.
In a big barn; there are often like minded folks. Ask them to go on a training trail ride with you and work with you. Then thank them a lot (cold drink? lunch/something) and reciprocate with some service you can do for them. You can take turns and celebrate your progress. They wait for you and you wait for them
But truly, a like minded fun trail riding buddy is worth their weight in gold. Cherish & nurture them!! jmho!