why do small indie films need AD's and such

I absolutely have come out of a shoot regretting the influence I allowed other people to have on me. I've tried to remedy that. You can't be closed minded to suggestions and ideas, but you have to have the courage of your convictions that allows you to stick pretty closely to your vision.

There's certainly nothing wrong with trying someone else's idea -- if schedule and budget allow. From time to time they might actually be right, and in the edit suite, it's possible their idea works better with the overall cut than your idea did. BUT, at the end of the day, if there's not time and budget to try a bunch of different things that aren't already planned for, a good director needs to have the strength to tell that crew/cast member it's not happening that way.

Most indie low budget films are done without much pre-planning, so when you go shoot everything is chaotic and you feel you need more crew.

Also, every movie has it's own needs and requires a different crew setup. An AD can be useful but more useful is to have a clear plan on the first day you're shooting.

I favor a small, highly experienced crew where everyone knows what they're doing and they know how to quickly fix problems. That inspires confidence to the actors and everything tends to move smoothly... 1st AD or not.

"Most indie low budget films are done without much pre-planning, so when you go shoot everything is chaotic and you feel you need more crew. "

I mean I guess a lot are at one end of the spectrum, but as we should all know low budget requires much MORE planning. I think I did 4 months of pre-production on my last 12 minute short.