There were two separate leave campaigns, the official one was lead by Boris and Gove, Farage headed up the other. There were disagreements at the start as to which would become the official campaign and whether they would combine. I'm not just calling it official because of the personnel, it's a real thing
Of course they didn't have any power to deliver what they were suggesting though, that should have been clear to everyone. They would need to be a leader of a majority government to actually be sure of delivering on what they were saying. It was all spoken about in absolutes instead of possibilities. The stuff that came out from both sides was absolutely ridiculous and I've got no idea why anyone believed most of the crap being spouted.
Edit: also I'm pretty sure Farage didn't push the £350 million for the NHS rubbish, and in particular didn't make any promises, if you can find a source I'll gladly admit I'm wrong though.