After 25 years of playing electric guitar in rock bands - then 'returning' to folk some four years back, I found far too many acoustic guitar necks too 'thick' for me (depth, front to back).
Our local guitar makers (Oakwood) here in Leeds (West Yorkshire, England) talked through my 'problems' with me, then made two guitars (based on a model of theirs where I liked everything BUT the neck) for me with neck specifictions of my own choosing.
I've ended up with two hand-made guitars with necks EXACTLY how I like 'em.
By working with a 'local' guitar maker, I believe I have superb quality and playability (to my specific requirements) at a slightly cheaper price than for similar quality materials and workmanship from the 'bigger name brands'.
I'm not on commision for Oakwood! - merely offering the suggestion that you can get as thin a neck as you desire - just go seek out your own 'local' luthier. Cheers! Duncan McFarlane