Despite their name, I think followers were never meant to follow the PC in her adventures. They are meant to take care of your businesses
while you go to adventures.
The cohort on the other hand is meant as a party support, in fact he is a classed NPC.
Personally I've always told my players that the cost of one feat to take Leadership is in exchange for
loyalty. You don't have to RP being kind and generous to your cohort and followers, they will be utterly loyal to you when you have the Leadership feat. Otherwise why the feat cost? You could have just tried to gain followers through roleplay... Notice in fact that evil characters are totally entitled to getting the Leadership feat too. There are penalties to the Leadership
score that can be triggered by mistreating them, but the score affects the number of followers and the cohort's level, not the loyalty of those who you are entitled to have.
But taking the followers with you inside a dungeon is beyond the scope of the feat. Maybe your case is more complicated because your followers drive your ship, so they are coming with you wherever you go
geographically, but then once you're in a location, they would faithfully tend to your ship, take care of shopping for supplies etc, but that doesn't mean they are willing to follow you into an Orc's encampment or a Dragon's lair. It's not their job.
Think of them as loyal fans or "supporter", like the fans of a boxe or wrestling champion: they might be willing to do his laundry and mop his floor, but they won't go into the ring and get the punches in his place!
