As for Yon's post, yes and no.

He's got a good point, and saying you should focus on the opinions of guys in "field-grade ranks" (majors to colonels) is generally good advice.

Some caveats, but first, some background. Field-grade officers often coming out of or heading to command were precisely who I used to teach. I got to know (as in working with every day for a year) about a dozen battalion commanders with Iraq or Afghanistan experience (several of whom are now brigade commanders). I also got to work with a similar number who'd had staff positions at higher-level headquarters, i.e., doing analysis work for a general, and met lots and lots of that sort.

That a battalion commander is often in the right position to know what's going on of often true, but not always. Higher-level staffs, especially at the MNF-Iraq level, can pull together lots of different sources of information. Battalion commanders won't know much about quiet but important aspects of the campaign, like what secret special forces teams are up to, or intel gathered from the CIA/NSA/etc. The battalion commanders also don't have the time do to much analysis and stock-taking, nor do they have the staff to do so. While the general commanding that HQ might be too political (and too much the detached CEO to know the details), a frank interview with a LTC or COL working for that general is often extremely useful. They are, literally, the guys who put it all together. You really want to combine the feel on the ground with the guys who've crunched all the data.

Second, my experience is that some of the commanders are too emotionally involved to step back and be objective. This is different than being political. But when you've sent 25 guys home in caskets, it's very, very hard to say that things are getting worse, or your efforts aren't very effective, even if that's true. Questioning outcomes becomes tantamount to questioning honor. I've known some commanders who could be very realistic and step back. I've known others who couldn't distinguish between questioning -- even by themselves -- whether their efforts were _working_, and questioning whether their cause was worthy, their committment 100%, their losses meaningful.